Novatel's U727 EVDO Rev. A USB cellular modem is small, fast and works seamlessly with Windows PCs and Macs.
Though an improvement over earlier models like the U720, it's still larger than most thumbdrives and those looking for something super-tiny will be disappointed. Joel bought one and sent it back, disappointed by its size, but I have no problem with it at all. It's one of the few things of its type that even fits in a MacBook Air.
Setup is easier on Windows: plug it in, and the software autoruns and configures it automagically. On OS X 10.4, instructions are provided, but they didn't quite match up to reality, and you have to find your way to Internet Connect and punch some stuff in manually. Not a major problem – especially for anyone who has ever hacked a WiFi or WWAN stick to work on OSX – but this flashback to the dial-up era may give delicate Mac fans the vapors.
Throughput was excellent in my location: 1.3 Mbps down and 500 kbps up on either platform, though it seems quite sensitive to location: moving a laptop just a few yards halved that.
The stick's antenna is attractive enough, flush with its geometry when closed and not unattractive when up. There's also a tiny connector for connecting an external antenna.
One untested bonus is the MicroSD card slot; it works as a card reader for cards up to 4GB.
I've been using this all week as my iMac's sole internet connection, and haven't noticed much difference at all between it and Comcast cable internet for everyday browsing. Sprint's EVDO service is fine, assuming you get a decent connection: the iMac's web server is not accessible with the stick's global IP address, however, so perhaps there's some sanitization of connections going on. There's no noticeable degradation of images or other suggestions of "speed-boosting" proxies.
The U727 costs $280 outright or is $80 with a 2-year contract subsidy with Sprint, on whose network it was tested. You'll need the $60 unlimited plan, as EVDO will eat the $40 40Mb plan in a few minutes.