are you looking to print on the road direct from your treo? or will you be able to use your desktop/laptop and existing printer? If you'll have access to your computer when you need to print, here is a free solution:
1)download
Remote Display Control for Pocket PC direct from Microsoft.
2) install on both PC and PPC
3) Use Remote Display Control to navigate to the "screen" you want to print from your Treo
4) Take a screen shot of the image
5) Paste into Photoshop/Pain/etc., crop to what you want to print, print from your printer.
hope that helps. Brad