I would like to add a feature to my website similar to Gowalla and Facebook that asks a user for their yahoo email address and password. The site fetches this users yahoo contact list and displays on screen. The user can choose as many of their yahoo contacts as they want and send them invites to join Facebook/Gowalla. That's it.
So, my application will ask a user for their yahoo username/pwd then return a list of contact firstname, lastname and email address. Nothing more. What is the easiest way to do this? I'm a C# .net developer and our website runs in IIS.
PS. It took me about 2 hrs to build a similar feature for gmail accounts. I downloaded an API, found a quick tutorial, instantiated a few business objects passing in the google username/pwd and I was crawling contact lists like crazy. Can I get something going really quick with yahoo that doesn't require I learn another language? I've spent two days researching/reading yahoo information on this and am totally lost.