ive tried slideit, shapewriter, and swype.....in terms of performance slideit is the best but its ugly looking..........swype is very good but can be laggy....nevertheless it can still be found even though its not on the market and the beta is no longer available. it just takes a lot of searching for the .apk, and then its a matter of finding the .apk that is compatible with Android 1.5....i finally found it and i am currently using it
but be warned, it takes up A LOT of storage memory
recommended sites for .apks:
mobilerumor.blogspot.com (android specific)
filecrop.com
4shared.com