It's *really* easy to get one-time parking permits from Traffic and Parking. It's $1 per car, although I got 10 for free back in November. Just go here (http://www.somervillema.gov/section.cfm?org=traffic&page=916) to apply for them.

That said, since parking is such a big issue, when we have parties I typically ask people to carpool and use the municipal lots as much as possible, too.