My gym routine. Swim for 20-30 minutes, then shower very quickly, hit the weight room, starting with an elliptical (or anything cardio) to get my heart rate back up. Then I focus on my muscle group of the day.
1st day of the week - Chest
2nd - Back
3rd - Shoulders
4th - Arms
5th - Finishers (defined as push-ups, dips, pull-ups, etc. Exercises that target more muscle groups than say a bench press does).
2 rest days per week thrown in usually by necessity because of other obligations. You know, the real life type stuff.
I do abdominals every day. I don't rest in between exercises, that's when I do my abs. I only take 15-30 seconds between sets to rest in order to keep my heart rate up.
Then after each weight workout it's back to the cardio. Usually in the form of the treadmill, running for another 1/2 hour.
Then there's cycling and running outside which are seperate from the above.
Obviously it's not a workout designed to make you big, but I am 6' and about 185 lbs with about 11% body fat. So, it hasn't exactly made me small either. But I keep my intensity way up while lifting weights. That's key to building mass.