I've always heard that strength work with weights helps burn calories twice - once while you are doing the exercise and the second time when the muscles are at rest as the 'repair' themselves. That arm workout sounds like a good idea.

On the bike, it is good to alternate going fast and then a slower pace. You can do 2 minutes fast and 5 minutes slow and then 2 minutes and 5 minutes slow. The interval approach like that helps burn more calories too.