You may have heard about this whole "social networking" thing by now, huh? It turns out that there are these web sites out there, where sometimes people make with the clickety-pokety and tell each other what shows they're going to. The less useless of these sites tend to have a shiny, candy-like "I'M GOING!" button on them, the better to browbeat your friends (and "friends") into attending with you. It's all very Modern.
That's kind of verbose, and I think it's a little weird to spell that all out in sentence form on every calendar entry, but I'm not sure how else to do it that would cause people to actually get the message, since this is apparently an unusual thing to do!
There are a few sites like ShareThis that let you put a little popup-menu dingus on your web pages to make it easy to submit your page's link to various link-aggregation sites. But, these widgets all seem to only really work with "bookmark"-type sites like Digg. I expected to find (and was surprised not to find) a similar widget for "event"-type sites, that would give you a widget that would let you easily direct-link to the various "I'm Going" buttons. But, it doesn't exist (and in hindsight, it's obvious why: it's really hard). So, the best we can do, I think, is make plain-old-links to the event pages on those other sites.
It's a real pain in the ass submitting our events to all of these sites. Most of them have no way to subscribe to our iCal or RSS feeds, so they all have to be entered manually. Some take HTML, some don't. Some screen-scrape MySpace, so you have to post to those before posting to MySpace or they get incomplete info. Most don't check for duplicate events, so if "DNA Lounge" posts an event, and the outside promoter of the event posts it as well, well then, there are two.
It's all a big hairy mess.