I found a nice gadget to allow visitors to your site/blog/whatever to chat with you through the site. It works using Google Talk (aka the chat window in gmail; it's also a standalone app). How it works it you first have to have a Google Talk account. Then you get a little badge to put on your site wherever you want. When your account is logged in, the badge shows that you are available and people can chat with you. They do not have to have Google Talk accounts. When they click the link, you get sent a message with option to accept and talk to whoever it is.
It's much better described here: http://www.google.com/support/talk/bin/answer.py?hl=en&answer=86171
NOTE: I had a lot of trouble with it today. I first signed up for a Google Talk account with an email address at one of my domains, and it wouldn't work. Later, after I changed it to my Gmail account, it worked fine. This may have been coincidence, judging by the support threads, but just in case...
