Try dancing to fast paced songs for a half hour. If you have a dog, take it for a walk. I love to kickbox, it's pretty fun...If you have a partner, you can get gloves and pads and spar at their hands.
Do you have any parks nearby? Go hiking, it's fun and good exercise. Go to the mall and walk...bonus b/c you can window shop and look at the clothes you will buy as a result of working out :-D.
I like to swim as well. I dont know if you have kids ( I dont) but you could play 4 square or kickball with them. You could also jump rope with a really big rope (you need two other people) and that would be fun as well if you have kids.
You could also go roller/ice skating or biking.
Hope this helps...good luck and stay motivated