Macitt, a social Mac news site from Apple Matters a lá digg and Netscape, has announced a year of monthly sponsored contests for 2007. For January, they're kicking off strong with a Mac mini. The only thing you need to do to enter the contest is participate in 3's each day: either 3 macitt votes, 3 comments, or 3 story submissions per day. Users are allowed to enter each day, but spamming and gaming the system are of course not allowed: no one-word answers, and no links to your mother's blog about knitting (though it might fly if she knit, say, an afghan with an Apple logo).
Check out macitt's contest page for more details, and good luck on that Mac mini.