CodeIgniter is currently my framework of choice. I love it's small size and useful libraries I try to contribute as much as I can on the CodeIgniter wiki. With handy helpers and libraries like: OAuth Helper and Language Library Extension I have a ton of libraries besides those which I will probably share on this site instead of the Wiki which is a bit bloated and difficult to navigate.
OAuth Helper is meant to aid in signing OAuth requests which can be pretty tricky. All you do is provide your consumer key, consumer secret (either a string or a path to a .pem cert file), then also an array of additional parameters (so if you have an oauth_token and oauth_token_secret)
The Language library extension provides some functionality which seems to be missing from the stock CodeIgniter language library, which is the ability to add a parameter to a language string. It uses standard sprintf notation in the language line and takes passed in parameters of either a single string or an array of strings.