I found this page on a quick Google search. I'd try showguy's suggestion first. If that doesn't work then give this page a look. I didn't read the whole thing but I think they're suggesting you use the CSV approach.
July 22, 2007
My wife and I just bought an iPhone and wanted to transfer our contacts from our Samsung i500 Palm phone. All the instructions I found online suggested going through Outlook, but that didn't work for me for a variety of reasons. I found this other method that worked really well.
Bring up Palm Desktop. Make sure your Palm phone is sync'ed up. Show the Address page, select all contacts (Ctrl-A), and export them with File, Export vCard... This puts all contact information into a single file as a sequence of vCards.
Bring up Windows Address Book. You can find this in Start, All Program, Accessories, Address Book.
Using Windows Explorer, drag the vCard file you created in step 1 to the Windows Address Book window. I had never used Windows Address Book, so it was empty. If yours isn't empty, you'll have to decide whether you want to merge your contacts.
When you drop the file, you'll get a window asking you to confirm the first contact. Press OK. Another window will come up for the second contact. Press OK until all windows are gone. It's easiest to hold down the Enter key.
Bring up iTunes with your iPhone plugged in. Go to your iPhone page, to the Info tab, and configure it to sync from Windows Address Book. Click Apply in the lower-right corner of the window.
Sync your iPhone. Verify that your contacts transferred over.
Tell iTunes to stop sync'ing with Windows Address Book, since you probably only wanted a one-way sync. Your contacts will be backed up anyway by iTunes, so the Address Book sync feature doesn't buy you much.