In some respects, you should keep your laptop home when you go on vacation. But I take one as my wife and I are retired, and we like to put those "wish you were here" messages on Facebook for our family and friends. So if you are going to take a computer, what do you take?
For light weight travelling, a netbook cannot be beat. They are usually fairly small and lighter weight than a laptop, and in many ways, easier to lug around. And they are typically cheaper, so if it's lost or stolen, then its not as much of a problem.
There is some criticism of netbooks in that they are a lot slower than laptops, and this is true. But I have pretty much alleviated that problem by using an operating system called Ubuntu, which is a form of Linux. Ubuntu is free, and is very fast - so much so that some applications load on my netbook than do on my laptop (which stays home).
If you don't wish to use Linux, or if you need to use windows occasionally, you can dual-boot your netbook, which is actually what I do. I use Ubuntu for most of my needs, but use Windows only on a rare occasion. What is lightning fast in Ubuntu runs like a dog in Windows XP.
But if you do not want to run anything but Windows, what then? Is a netbook sufficient? To determine this, figure out what you want the netbook to do. My needs were:
If you are primarily using your netbook for these needs, Windows is sufficient. However, since I installed Ubuntu, I have found that some photo editing is completely satisfactory. I tend to use Adobe Photoshop Lightroom for my photo editing needs on my laptop at home, but I can also use Gimp (free for individual use) on the Netbook, in either Windows or Ubuntu (there is a version for each). And, a minimal editing and viewing program called FastStone (also a free program for individual use), although only a Windows version, will run under Ubuntu if you use Wine (a Linux Windows emulator you can download on your Ubuntu system).
Laptop: Everything that I take is shown here; an Acer Aspire One D250 10.5in Netbook and a Think Tank Cable Management 20 bag with all of the accessories. While my netbook model is no longer available, it's replacement model is. When I installed Ubuntu, I upgraded the Acer netbook to 2Gb of RAM and a 500Mb hard drive. I would not normally recommend upgrading a netbook with more RAM and hard drive as soon you get into the price range of a laptop; however, in this limited application (portability), and when using Ubuntu (where the additional RAM can be readily used), it can be justified.
WiFi: WiFi is expensive on board the ship, somewhere in the range of $75 per hour. For this reason, if you use your netbook, compose your email prior to logging in, so that you can transmit and receive quickly and log off again. In addition to the expense, network speeds on board are fairly slow, somewhere between DSL and Dial up Modems. If you are used to Broadband Cable Modem speeds, you will be in for a shock.
A WiFi alternative is to use free WiFi when you reach your port-of-call. Most of the crew know where the hotspots are, so if you talk to your cabin attendant, you'll able fo find where they go. Just take your netbook with you when you go ashore for the day and do your email transactions then. This is another great reason for carrying a netbook.
I have also used an Apple iPod Touch for email and Facebook via WiFi, and it works great for that as well, however, you will not be able to view photos as well as using a netbook, if that is important to you. Sure, you can use an iPad, but a netbook is less expensive, and if it gets lost, stolen, or broken, its not as bad.
Passwords: Another good reason for using Ubuntu is it has good security, as long as you setup your PC to require passwords with a STRONG password (that is, one hard to hack). In the event it is stolen, hopefully no one will be able to hack into it. Of course, if you are using Windows or an iPad/iPod/iPhone, you will also want to password protect it as well.
A strong password would be one with a minimum of 8 characters, and a combination of at least one UPPER CASE character, LOWER CASE character, a SPECIAL character (such as ! $ % ^ * .), and a letter. Ideally you will not use any dictonary words or anything that can be associated with you, such as children's names, etc.
The above password would fit the STRONG password requirement; it is 8 characters (but it could be longer), no dictonary words (Go and f1sh have separating characters), and in addition to lower case letters, it has a Capital letter "G", a number "1", and a special character repeated twice ".". This password would be difficult to bypass.
Accessory Pouch: The contents of the accessory pouch include; AC adapter and charging cable for the netbook, Belkin Retractable Travel Mouse, Transcend Portable Hard Drive, and a Virgin Mobile 2200 MiFi Hotspot.
Of course, at the risk of increasing the "junk-you-take-with-you" factor, all of this stuff isn't truly necessary. Of course, the netbook's AC adapter is necessary, as well as the mouse - if you plan on doing any photo editing. The portable hard drive is nice to have as I typically download a copy of the photos I take to it. I always leave the hard drive in the cabin, so if the netbook should become broken or stolen, I'll still have a copy of the photos. Having two copies means I can erase the camera memory cards if needed with the confidence I won't lose the photos. Lastly, while I show the Transcend drive model I have, I would recommend their ruggedized version if you are taking it on board.
The WiFi hotspot is of little use in the Caribbean. It is essentially a router that allows up to 5 WiFi devices to connect via 3G network to the internet. However, in the Caribbean, 3G - if it is available, is going to be expensive. But we typically drive to Florida from Michigan for our cruises, which is a 2 day trip. It's nice to have internet available in the car to check on hotels, the weather, and other information along the way. Rather than dumping it off in the glovebox, I simply leave it with the netbook.
There are several versions of this hotspot, one by Virgin Mobile and one by Verizon. However, the Virgin Mobile plan is a no-contract plan, and costs $40 for unlimited data (as of this writing). And you can elect to pay for only the months you actually use it. So we typically use it a couple of times a year; each time we cruise. As long as you use it once a year, your account will stay open.
Summary: While this may or may not be the ideal solution for you, its what I have found that works best for me. Hopefully I will at least provide you with some insight to why I have chosen this equipment, as well as tips such as using the free WiFi hotspots the ship's crew uses. I am providing links to the items I have purchased so you can get an idea of their cost.