You don't feel like taking on a programming challenge?
A very long time ago (it hasn't worked since Fx version 3.5) Ciberblade made a TSG
add-on for firefox. I'm sure that the same sort of thing could be made for Chrome. I don't know how, but that's normal for new ideas.
However if I remember correctly (I'll check in a minute), that particular add-on just added a menu of links for getting to the different fora.
If you want something that is more interactive, such as informing you of interesting new things, the programming task gets harder fast.
1. You need to think about security/identification.
2. You need a permanent AJAX style link to the server, or at least need to be regularly querying it for new information. You'd also want to think about the possible bandwidth implications of this.
3. You need extra code on the server allowing it to respond appropriately to said queries. This is possible (combine "my account", the notification area, and some sort of "unread threads" code) but an additional hurdle. In other words, it can't just be an initiative by one member.
Then of course you need to think about the logos, menu, whether it changes colour when there's something juicy, all the normal challenges of a programmer.
None of these are necessarily prohibitive, and of course it depends on what you actually have in mind. Definitely a good idea though.