How do I transfer my contacts from a Sprint Sanyo "flip-phone" to my new iPhone 4S ?

The first thing to do is getting them out of the Sanyo Phone. you'll need to find that out from Sanyo depending on how they are stored it may not even be possible to get them out other than writign them down. You can then copy them to either Outlook on a PC or Contacts on a Mac and use iTunes to sync them.

for contacts only if you dont want to use backup I use the app MCBackup