Chris, for smoke times in that time range, there isn't much you can cook and do it well, but a few suggestions I would make that I have personally done are ribs (They only take about 2 - 3 hours and they come out very moist and tender).
Beer Can Chicken - get some whole chickens, a chicken holder and follow these instructions....Very important....Drink half the can of beer...I know that is the toughest part about this, but it is very important :D , next, put your rub on the chicken, what ever is left over, put some inside the chicken and some in the can of beer. Then put the Beer in the holder, the chicken on the holder and put it in the smoker. The cook time for this is about 2 -3 hours and it will be the most tender, best tasting chicken you have ever had.
Small Pork Loin - If it is small enough, you will be able to smoke it in the time you want and depending upon how well your rub and smoke are, it will come out very mosit as well.
Hope this helps, now you have made me hungry for some BBQ.
Enjoy!!!