I don't think that there is currently anything available that has desktop and PPC versions. I use
DVD Profiler on my desktop, and it is absolutely the best DVD catalog I've used. It uses your net access, and all you do is type in the UPC code from the DVD box.....it puts up the rest of the information for you. Out of around 120+ DVDs, I have yet to enter one that is not in their database already. If you don't want to do it via UPC, you can do it via Title as well.
Anyhow DVD Profiler has an option to export as either a CSV file or an XML file. Therefore, if you had a DVD catalog for Pocket PC that could import either of these files....it could be done with little problem. I think DVDx for Pocket PC might import CSV files, but I am not positive.
As a side note, there is a menu option in the most recent (a few months old) release of DVD Profiler to "Export to DVD Profiler Pocket." This has led many people to believe that Intervocative is working on a Pocket PC (or PalmOS possibly?) release of DVD Profiler. However, they have yet to comment on this over the past few months.