My contract is up, and I am ready for a new phone. If it is possible, I want to stay with T-Mobile, but I don't mind switching carrier. The next phone should be Windows Mobile Prof, GPS, Wifi, fast response UI (like Palm OS), thin (like iphone), and light weight. Would you recommend me one? Oh, my mother often has problem hearing me on my current cell phone, so my next phone must have excellent outgoing voice. I don't want to be in trouble with my mom. Thank you.
Hate to tell you, but T-Mobile has nothing that matches your requests. Their WinMo Pro phone, the Wing, is slow and lacks GPS.
AT&T has a better selection, though nothing slim and light that also has all those features and runs the Pro version of WinMo. There are recently released unlocked GSM phones that do match-- the HTC Touch Diamond seems like a perfect match and it's even very slim and light. Mom will like the voice quality-- my mom does . Here's our review: http://www.mobiletechreview.com/phones/HTC-Touch-Diamond.htm . It sells for around $650 though-- not cheap. You might want to take a subsidized phone on a new contract and sell it to help partially pay for the Diamond.
A very recent phone is the Samsung Omnia 900 (just came out a few weeks ago). It's another good match, though not as small as the Diamond. However, it's even harder to find and more expensive.
-------------------- Lisa Gade Editor in Chief, MobileTechReview