Like many families, we travel with a multitude of internet capable devices- laptop, smartphone, video games etc. I have an unlocked 3G dongle and a collection of pre-paid SIM cards for the countries we visit most often. In order to be able to share the connection provided by the dongle, we needed a router that will accept the dongle and provide WLAN (preferably "n") for the kit that the family uses.
Right now the dongle (Huawei E1750) is giving us a 7.2MBps link that is being shared by the Solwise router with two notebooks, a smart-phone, and a PSP. We're reading/sending mail, uploading photos and video-calling on Skype- and it's working great !
The Solwise router is very well priced, very well built and very easy to set-up and operate (I disagree with the reviewer who thought that this was a complicated device). If you plan to use SIM cards from different providers you'll need to create separate profiles to store the connection settings, but you'd have to do the same on your laptop anyway.
I really like the power options- you can plug directly into the wall (240, 110 volts), there's a European adapter available on Amazon, the kit includes a 12 volt jack adapter, AND you can power it with a mini-USB cable. So you could even have internet in the car if you want !
The webcam, SAMBA, FTP server functions are handy (if your 3G dongle has a micro-SD card slot you can use it as a portable file-server).