A friend of mine has a Treo 650 on Verizon.  I use Alltel, a regional
CDMA provider.  He's thinking about updating to a Treo 700p, and I was
wondering if it would be possible for me to use his phone with my
service.

First, there is a new ringtone creator that now not only creates
ringtones, but also sends photos from photo files (it also even does
screencapture), and video to a phone (if your phone can handle video).
Second app is My Files Watcher, which will let you know with a text

T-Mobile's prepaid service has been one of the best prepaid services due
to their low cost (10 cents per minute) and 1 year expiration (rather
than 30, 60, 90, or 120 days like most prepaid carriers). But a major
limitation was the you could not roam onto 800 Mhz prepaid networks ...

The ACSI measures consumer satisfaction across a range of goods and
services.
See "http://www.theacsi.org/press_releases/0506q1.htm"
"The wireless telephone service industry improved 5% this year to 66 –

See:
"http://seattlepi.nwsource.com/business/270325_consumersatisfaction16.html"
A good article about how T-Mobile's honesty about coverage has improved
their satisfaction ratings.