It's no secret many iPhone users switched over from PalmOS Treo devices (yours truly included!) and now StyleTap has brought a way for you to run all your old PalmOS apps on your Jailbroken iPhone. Says Engadget:
you'll be able to run Palm OS applications (compatible up to version 5.2), with support for native ARM apps, Audio recording and playback, virtual memory cards, and TCP/IP connectivity, amongst other features.
The cost is a not-so-insignificant $49.99 and will only work for as long as you keep your iPhone jailbroken (which means no iPhone 4.0 for you for a while at least!) but if there's just something you gotta blast from your PalmOS past, check it out.