I'm on Day 11 today, and I'm thinking of starting a second challenge... is there anything in the rules about doing 2 challenges at the same time, but counting the days separately?
If that's against the rules, then I'm just going to do my own independent 28-day challenge - crunches. Yes, 28 days of crunches, starting at 5 and adding one more each day or every second day.
Either way, I completed Day 2 this morning. I did 5 yesterday, and it was a good number to pick, as the last one nearly killed me!

Today I did 6.
I don't have any way to measure the distance I'm running, other than "two times from the hole in the road to the big tree overthere and back." And I don't have a real stopwatch either, so I'm running with my cell phone! How pathetic is that?!

But it lets me take snapshots, so I know exactly when I take breaks and how long they are
Stats
Days 1 to 5: no stats kept, but it went from 5-6 minutes to close to 10
Day 6 - 11 mins 30 sec with 2 breaks; 8 mins 14 seconds running, first break at 3 min 41 sec
free day (migraine)
Day 7 - 15 mins 4 seconds with 2 breaks; 11 min 20 sec running, first break at 4 min 30 sec
Day 8 - run 0 to 4 mins 32 sec, walk 4'32" to 6'27" and run 6'27" to 7'30" - so total time ran 5 min 35 sec
Day 9 - run to 3'47", walk to 6'40", run to 9'56", walk to 12'22", run to 13'52" so total time ran is 8 minutes 33 seconds
Day 10 - run 0-3'46", walk to 6'42", run to 9'46" (3"4'), walk to 12'53' and run to 15'57" (3'4" - yay!), total time ran is 9 min 54 sec