I guess the Facebook icons are standardized, but I find that the new f-Like button dominates the pages like, for example, the comments.
The Twitter button is much more subtle! I would say, "It's not just the size that's annoying, it's the blue background"!
If you "like" it, the blue is more dignified!
A http://www.migipedia.ch/sites/all/themes/migipedia/img/icons/facebook.gif would be enough!