This is a great plugin you've created here. Very cool stuff.
I recently posted a simple plugin that pulls Tweets called Tweeple. I'm using the same version of the thmOAuth class in my plugin as you're using.
I have a couple of users that using our plugins together, and the activation of your plugin seems to kill my plugin's communication with Twitter. I was digging through a bit and found that it's this stray line that has crept into your copy of the thmOAuth class which seems to be doing it.
Line 609: `$params = array( 'Just testing' );
Commenting out that line in your thmOAuth class brings everything back with my plugin. Anyway, just wanted to let you know, as I have a couple people wanting to use our two plugins together.