i find a problem that i have with posting on other blogs is i will rarely check back to see if someone replied to my comment. it's far more efficient on sites like facebook or forums where you get the notifications. i'm wondering if anyone has installed a 3rd party commenting engine on their site to handle this sort of thing?

some things that i know exist is Google's OpenSocial platform, also maybe you can also use Facebook Connect. the problem with these is that people who don't have accounts on the service will be disengaged which isn't a good thing.

i currently use textpattern as my main cms and blogging tool but the discussion is kind of irrelevant as to which is your main tool.