Go OP go! I just started the couch to 5k program too, and am somewhere in week 2. It feels so good to run - I love the feeling of tired muscles afterwards.
I've also been doing some exercise challenges with friends of mine online - right now it's an Ab Challenge month, so we alternate days of doing various things. Many have never done this stuff before - we just look for instructions on youtube or whatever and put them on our calendars each day for a month! We've been doing (day 1) - 30 bicycle crunches. 30 sec plank, 30 sec mountain climbers; (day 2) - 20 reverse crunches, 1 min burpees, 20 supermans.
Here are some similar ideas:
http://30dayfitnesschallenges.com/ I find that the 30 day thing helps keep me motivated - it's not so long to do something, and the exercises are usually quick.