I'm thinking of trading in my Verizon Treo 700p for a Verizon 8830 so I can use it overseas.

I have a question. I know if I add international service I can use the phone and send and receive email globally....but...can I also use the data service on the 8830 overseas? In other words, get news, weather, stock info, check flight info, etc via the Blackberry browser? I'd like to hear from anyone who has done this, especially in Europe, to see how it was. Thanks.

No issues that I've heard of; personally tested out last week with UK, Germany & Italy; the $64.99 monthly Global Data package gives you unlimited email, internet, PIN to PIN messaging, BB Messenger, stock quotes, weather, etc. etc. with no hidden charges, in every country that VZW has a roaming agreement with.
Make sure to get the Global Package - Vodafone SIM card, global support booklet etc. etc.

Ditto... worked good for me in Sicily, Rome & Madrid.

Worked like a charm over in China. I had to use GSM for data service and CDMA for calls but it wasn't a big deal.