SkypeSync ports your mobile phone contacts to Skype
Here's how to use it: point your phone's browser at zyb.com, a free synchronization server recently acquired by Vodafone, and store your contacts there. Download and open SkypeSync (it's only available for Windows right now) and use its Synchronization Wizard to import your contacts from Zyb to Skype. Voila! You now have all your phone numbers ready for use with SkypeOut.
Obviously, the service is somewhat limited right now, since it only works with Zyb, but there are plans to support other synchronization servers soon. Right now, this looks like a decent solution if you're a big SkypeOut user, and don't want to face the prospect of manually entering every number you want to call on Skype.