I realize this post is oooold, but I thought I'd share my recent experience getting my trusty Imagio to work at 3G speeds on the Vodafone network in London, England.
First, I can confirm all the info regarding the call to Verizon Global. It is true that you can get a SIM Unlock code for free if your account is in good standing. I don't believe it has been mentioned in this thread yet, however, that you won't get another SIM unlock code from Verizon for six months, even if you renew a contract in the meantime. Of course, you can always pay for a code (just Google for SIM unlock code) if you do upgrade before six months.
So, I went to London for three weeks and bought a pay-as-you-go SIM card from Vodafone for only GBP 10 (about USD 15). Putting in the card and getting voice and SMS was a snap. But, getting the phone to associate properly with the Vodafone data network took some doing. The following instructions come from the Vodafone UK website and are for the Rhodium:
HTC Touch Pro 2 (WM 6.5)
How to configure your device for Internet
1. Tap Start
2. Tap Settings
3. Tap All Settings
4. Tap Connections
5. Tap Connections
6. Tap Manage existing connections
7. Tap New
8. Tap the box under Enter a name for the connection
9. Enter Vodafone Internet
10. Tap the drop-down arrow below Select a modem
11. Tap Cellular Line (GPRS, 3G)
12. Tap Next
13. In the box under Access point name, enter:
For Pay monthly customers: internet
For Pay as you go customers: pp.vodafone.co.uk
14. Tap Next
15. In the box next to User name, enter web
16. In the box next to Password, enter web
17. Leave the box next to Domain blank
18. Tap Finish
19. Tap Vodafone Internet from the list
20. Tap ok.
Via mobilespeedtest.com, I was getting upwards of 900 kbps. That, according to the website, is 3G speeds, and indeed is just as fast as I get here in the States on Verizon. Hope this helps someone...it was a long time for me to figure all this out!
Another thing I did while overseas was to suspend my Verizon account without payment. This saved me about $70, and it's easy to do by calling *611 to suspend and reactivate.