Trusted Reviews has taken a look at the HTC Kaiser. The Kaiser is smaller than its predecessor, the T-Mobile Vario II, and much less of a "trouser-pocket bulger" according to the reviewer.

The Kaiser is a quad band phone with sliding qwerty keyboard and a 2.8 inch 240 x 320 touch screen. It supports HSDPA and 3G speeds as well as standard GPRS.
Check out the link below for the full review.

"With the P4550, HTC has taken what was already a competent smartphone and thought really hard about how to make it better. The result is a handset that does pretty much everything you could possibly want a handset to do. It'll work anywhere in the world, has fast data connections, a qwerty keyboard for fast and comfortable messaging, a tilting screen and even a GPS receiver for satellite navigation. Most importantly HTC has managed to package it all up in a highly usable, well-constructed and not-too-tubby package. When the time comes to move away from my current mobile phone contract and upgrade from my current phone, this is going to be the handset I'll be looking to replace it with. I can't praise it any higher than that."