StyleTap Platform is an application that promises to let you run Palm OS applications on your Windows Mobile Pocket PC. StyleTap™ Platform is fast, compact and comes with everything you need. Just add your favorite third-party applications for Palm OS® Platform and you’re ready to go! It does not provide hotsync capabilities.
A thread over at Brighthand has identified some issues. StyleTap is still in beta so some of these may get fixed by version 1.0 though.
StyleTap is currently available as a Preview Version which can be purchased for $29.95 USD. This includes a free upgrade to version 1.0 when it is released. A 14-day trial version is also available.