S3Kit is a collection of utilities that make it easier to access Amazon's S3 via their REST API. Currently, the main feature is a NSURLRequest subclass, BS3Request. This class can be used in place of a standard NSURLRequest to do a lot of the work involved in formatting and signing various requests to the REST API.
S3Kit is a static library and is best included as a sub-module of your app's Git repo. More detailed instructions coming soon.
BS3Request * request = [[BS3Request alloc] initWithAccessKey:@"KEYHERE" secretKey:@"KEYHERE"];
NSData *data = [NSURLConnection sendSynchronousRequest:request ...];
I will be updating the header files with documentation, check out the tests for some examples of different inputs.