I see that ebaY/Lithium took away the tweeter buttons from the pages... People are asking/wanting to tweet various topics posts etc.
Very simple. To tweet any page, go to Twitter developer page and drag the share bookmarklet onto your toolbar.
You'll need to have javascripting enabled for the button to work once you install it. (if you have a single button for simple allow/disallow)
If you use NoScript, and javascript is not enabled / whitelisted / allowed, for the page/domain you wish to share, it will cause the page title (or selected text) to not show in your tweet. You can paste or type it in or simply tweet the url only/add your own text etc without having to enable javascript for that page/domain.
If you use firefox you can easily customize your bookmarklet favicon with favicon picker extension, from addons.mozilla.org. In bookmark properties, you remove all text, thus being left with the favicon only.
It opens a small subwindow, or on some pages may open in new tab or full window depending on that page's own script.
My browser appearance is pretty modded, but here's how I have it, showing the tooltip flyout in action.
You can see the other favicons for tinyurl, longurl, and bitly. Same-same, google is your friend