This was my first venture into the world of smartphones and I thought I'd start with a cheap and cheerful entry-level phone. I regret not spending a little more to get a beter phone.
The onboard memory is only 150MB which is nowhere near enough. Install more than two or three applications and the memory manager will constantly whinge that "internal storage is critically low, increase storage space by removing unnecessary applications and data". You can move some apps to the SD card but other apps can't be moved at all (twitter, facebook, youtube, google maps, gmail, google calendar).
So this phone would be OK if it wasn't completely and utterly crippled by a lack of internal memory. It's a shame because otherwise its a reasonable phone, if HTC had been a bit less stingy with the memory then it wouldn't have been much better. Don't waste your money on it.