Mobile Broadband Rules
Having bought an eee some time ago I decided it made sense to accompany such a portable device with an equally portable connection of some kind so I bought me a 3 (UK) PAYG dongle (Huawei E220) for a pretty reasonable 40 quid. I'd read reviews and I'd heard the service was abysmal but never one to take reviews as gospel truth I figured I'd give it a go. At £10/1GB, £15/3GB or £25/7GB it's pricey to say the least (not to mention the fact that topups expire after 30 days). However, the convenience of being able to connect pretty much anywhere made me overlook the costs because I knew I'd only use it occasionally and I wouldn't be doing anything particularly heavy with it, that's what ADSL is for.
Now I'm glad I did, but right out of the box I wasn't quite as pleased. Trying to make the dongle install properly was a right pain in the ass despite the dongle having a U3-style flash based optical drive simulator with the drivers on it. The drivers are awful, the connection to the laptop would often just flat out die or it would seem to be connected yet would not be recognised. Terrible, pathetic, nasty, cheap... just plain crap. When I eventually got the thing installed, the device itself seemed stable but the connection it provided wasn't so much.
Now I've taken the SIM from the dongle and put it into an HTC Tytn II and it's absolutely brilliant. I don't get 3G at home but why would I need to when I have ADSL already? In an emergency though I can get GPRS which makes it a nice backup even if it's not particularly quick. Out and about, however, I do get HSDPA, and when I have that HSDPA it really is like having broadband in your pocket, it far surpassed my expectations. As an added bonus, with every topup I get 90 days of Skype traffic for free outside of my regular usage.
So in summary, if you have a decent device to connect with and you have a half decent signal, HSDPA rocks. If you have a cheaply made dongle with drivers that could've easily been written by a 5 year old and a mediocre signal then you'll probably be less lucky. It's extremely convenient but it's also extremely expensive. On the other hand, WIFI is faster and more consistent if you're not going anywhere. Most access points these days seem to be secured (so no "borrowing" WIFI) and I'm not sure I'd want to pay for a connection I could only use at (for example) Starbucks which is insecure and only works in one location when I could drop the same cash on a top up for my HSDPA and go anywhere with it.
Oh yeah, one final point, make sure you bring a portable nuclear power station, those HSDPA radios suck juice like a class full of preschoolers at cookie time.