I started using the pinned tabs feature in chrome, but I thought it would be awesome if I could get the unread count from a page's title from sites like Twitter (eg (2) Twitter / Home) and overlay that onto the favicon.
The result is a little buggy, but it works. I used HTML canvas to pull the current favicon and overlay the count onto it, then inject it back into the page.

Unread Count on the Chrome Web Store: https://chrome.google.com/webstore/detail/gaohofpopjedmgfigclabbgbnlgmajoa
Sorry, I should have added I'm on a Mac, latest version of OS X (Snow Leopard) and latest stable Chrome.
The above issues have been addressed with updates for anyone reading this, many thanks to Matt for the help!
Please look at the Firefox extension called Tab Badge Notifications. This Chrome extension should be more like that. Right now, the notifications on top of the favicons just doesn't work well. They aren't very noticeable, let alone really readable. Please steer this chrome extension closer to the way it is for the Firefox one.
Would love to utilize something similar to Tap Badge in Chrome (pinned tabs) and surprised it doesn't exist already. I'd be happy to pay for such an app! Any plans to develop such an app? Something specifically for Facebook. Keep up the great work! If not a counter in the favicon, then something more like this icon color change http://userscripts.org/scripts/show/1...
This app is fantastic, it does exactly what I want. The best part is that its not based on specific sites, just based on site title, so it works for our internal custom portal. The only issue I'm having is that I can't actually change any of the settings. For all of the text fields as soon as I enter anything it immediately gets erased.
Looks like my issue is on line 182 of the html in your custom script that checks "e.srcElement.checked". On the text fields this is always false and therefore sets the value to null.
Just to update people regarding the bug reported by @Kevin - I just pushed an update to the Web Store that fixes that.
Hi, I love this extension and it is exactly what I needed for pinned tabs, but I'm having two issues:
1. The font settings don't work, no matter what I do (they appear to save, but the same default font is used on the favicon badge all the time)
2. It doesn't appear to support Google+.