or you could just sell it to websites looking to SEO ^_^ reminds me of the dating site or whatever that had those surveys that people embedded everywhere, that's how they got to #2 or something for "free online dating"
The SEO angle won't work-- JavaScript widgets aren't seen by spiders nowadays. The SEO hackers who did what you're referring to added links below the javascript in the code they provided. Downside of this is that if the OP wants to go this route, he can't retroactively add a link to these current users. Unless the link/anchor text relates to widget, Google will ban your ass. The guy who did the online dating thing did in fact get slapped HARD by Google. You can read about it here: http://www.seomoz.org/blog/widgetbait-gone-wild
This is a pretty strong SEO technique. You should be doing that already. You don't need to stick unrelated links there, just link back to your Twitter-themed site.
Note: I wouldn't use the noscript tag. I'd either have a div that was replaced via javascript or a small/light chunk of html below the javascript. Pretty good chance of noscript tags getting dinged by Google given how they are being used.