I just recently took an epic deal on a Verizon Wireless UM150 modem for mobile internet - they mislabeled the item as "VERIZON COMPUTER USB TELEPHONE DEVICE WITH CASE" for $5. This card's MSRP was around $250 when they first came out, and modems like these go from about $80-100 on eBay, depending.
This thing has one of those 'daily access' passes for 24 hours for around $15, and I'm currently on their DayPass plan for the day.
I'm actually fairly surprised at mobile broadband - this feels like I'm still using my cable internet connection right now. I'm pulling on average about 1200 kbps (about 130-140 KB/second) and this is actually pleasant to use.
I'm also testing one thing out: The "on-contract" plans have a 5 gigabyte 'cap' after which overage charges apply. I'm going to go over 5 GB to see what happens, since I was not told that any overage charges would apply on this DayPass plan, which probably means I can download more than 5 GB without fees.
I'm up to almost 4.6 GB as I write this, and it's been about 12 and a half hours into my 24 hour pass.
Anyone else have experience with mobile broadband cards?