yeah, thats what I do!!!
I have been using the gtalk chat application on my windows desktop for quite some time now. Recently, I thought of trying out the GTalk Labs edition.
The Google Talk Labs Edition is wonderful. I liked the refreshing interface a lot. Besides, it allows you to use the invisible mode too!

The labs edition also has group chat which can be fun at times ;o) Orkut notifications as well as your google calendar notifications have been integrated.
Labs edition has been around for quite some time now and if you haven’t used it yet then do give it a try.
The Google Talk Labs Edition page says:
Features of the Google Talk Gadget on your desktop (emoticons, group chat, and more!)
New! Desktop notifications from the following services:
Gmail
Calendar (with a new snooze option!)
Orkut
kiran
November 23rd, 2008 at 10:28 am
i have been using it.
You did not reply to my previous comment/question.
Nischal Shetty
November 23rd, 2008 at 10:48 am
@Kiran
I checked out your site. It’s come out really well! Nice job
Abhimanyu
May 6th, 2009 at 7:20 am
you can also find some extra features on the labs version of other Google products which allows you to make yourself invisible but it does not always override the gtalk client software if you have that installed
http://mwolk.com/blog/how-to-stay-and-chat-invisible-and-as-offline-in-gtalk/