For a full list of city-owned rinks check out the Department of Conservation and Recreation. Most are free entry and offer cheap rentals, like Stony Brook's $2 skates. Unfortunately, you are no longer allowed to skate on the Jamaica Pond as this old-timey picture shows.
Kendall Square Rink Opening Party Saturday 11 AM - 9 PM
Free entry to the rink, ice show at 2 PM and free refreshments, which I'm hoping means hot chocolate and cookies.
Charles Hotel Rink Opening Party Sunday 12 -6 PM
This was supposed to be last week, but it was too warm. What's going on New England? So here's your chance - free performances at noon, free skating and rentals all day.
College Night at the Frog Pond Tuesday 5 - 9 PM
The Common's Frog Pond freezes over every winter to make the most picturesque, though pricey, skating spot. Tuesdays those with a college ID get a break - just $2 entry. Now where did I put that old ID?
There's a ton more going on this weekend - I Love Latkes Party in Harvard Square, Illumination Tour of Somerville, Battle of the Belgians at City Feed, Caroling Mob in JP - so check out the full calendar at the bottom of the site.