Allow other twitter-clones to create links, too

Thanks for the patch, I'll review it as soon as I get a chance.

Generally, the patch looks good, and I appreciate the work you've done on this. In terms of the actual code I just have one minor gripe:

+    drupal_alter('tweet_services');

That needs to have $services passed in as a parameter so modules that implement this have something to alter.

I think, though, that your approach requires a little too much work on the part of modules implementing the hook. I want the hook to return only keywords, not code -- that is, I don't want the client module to have to figure out where the icons are, or that theme('image') exists, etc. I'd like to see the "Text of link" function change to use a %service token have have the client hook just provide the name of the service instead of the full link text, for example.

I will think about this a little more and try to massage your patch tonight.

I created a new 4.x branch for these changes because they require changing the API. I would appreciate if you could try it out and see if it works for you.

I'm going to go ahead and mark this fixed. If any problems are found with the 4.x branch, or if anyone has a new service to contribute, please open a new issue.