PC & Tech Authority magazine are giving this away (or providing the access for Comodo to give it away).
Previous Comodo stuff has been ok (the free firewall), and this gets a good rating from the mag (not that that means much). I'd say worth a shot.
The sandbox feature is a good way to secure a browser (among other things), but is a bit tricky to use. (I've tried the free Bufferzone Pro one with clients prone to getting viruses and it was too hard for them use).
+Remember this same thing cost us $4 on Catch of the Day ;)