Jim, the Photobucket (PB) process for authenticating is modified OAUTH. If you start looking at OAUTH examples you will find that you can authenticate on PB by simply converting a sample over to PB. e.g.: There's an OAuth starter kit set up for LinkedIN by Lee WHitney on Github courtesy of Kirsten Jones. Register an app with PB, get your keys and plug in the keys & correct PB URLs and you will be working. The URLS you need are:-
requestTokenURLString = @"http://api.photobucket.com/login/request";
accessTokenURLString = @"http://api.photobucket.com/login/access";
userLoginURLString = @"http://photobucket.com/apilogin/login";
This will get you logged in but there's a lot more to come. PB have a code page and there is an Objective-C library including a modified OAUTH but it's missing docs so you need to work it out by studying the code. Bitbucket Photobucket code for objective-c
The issue I have is to do with their usage of sub domains and trying to get OAUTH to work with that.
UPDATE: Solved: I have at last worked out how to get a part of the provided API working in my own Xcode project. Basically I added the special Oauth files which enable the requests to be set up correctly to get round the subdomain stuff.
eg: OAuthASIHTTPRequest etc
I'm now getting full album info.