My input on your purchase, I would have chosen the Dec 3.5's or 4's instead, since they have so much more open interest. That said, I expect you'll make great money. It's a good play, and if you only purchased a small amount of calls then I doubt the lack of open interest will turn out to be all that risky.
I prefer more active volume as well, in addition to open interest, when trading calls, but I compromised a little on the volume myself with my own trade. There was more volume on the calls I chose than the others, but there still wasn't a lot, at least when I started.
I bought January 18 3's last week between $.43 and $.50, an average of about $.46. They are now at $.91... and I'm holding. There's a fundamental move going on here, and as tempting as it is to lock in profits now, with a little patience, this can go much, much higher over the next few months. Opportunities like this don't come along every day, or even every year.