I've used talk gadget to contact several people today, and it's working fine. I note that some of my contacts have a small circle next to their name, which is green when online and using your computer, orange when online but not using your computer, gray when off line, etc. But some people have no circle. I'm not sure why this is. Possibly they haven't added me to their own contact list?
It is possible to change the user name that appears when using talk gadget. If you want a different name, like the one you use on the blog, I think you can find the instructions by clicking help.