I have only tried this on my HTC EVO, and it works wonderfully.
- Download the apk file to your phone
- Enable "Unknows Sources" in Settings -> Applications
- Using a file browser like Astro, open up the apk file and install Swype
- Go to Settings-> Language & keyboards to enable swype
- In a text area, long press the text area and it will allow you to set the input method
It definitely takes some getting used to, but I believe Swype is the most efficient method of inputting text on the Android.