If you use Last.fm, you may have got around to using their events feature where you can search for events near you and mark yourself attending those events. I was manually entering the information into my google calendar, which was a pain.

Fortunately, being one of those hip, friendly web2.0 websites, Last.fm allows you to get your data out in all sorts of useful ways, including you event calendar as an iCal file. Google being useful, allow you to display external iCal files in your calendar. Can you see where I'm going with this? To get this up, log into you Google calendar, go to "Manage Calendars", then "Add Calendar", then "Public Calendar Address". Finally type in the url of your last.fm iCal file, which will be http://ws.audioscrobbler.com/1.0/user/dpash/events.ics, although obviously you need to change dpash to your particular last.fm username. Now, you only need to mark yourself attending a gig to have it show up in your Google calendar.

You can use something like this to get it into your Evolution calendar.