hey N.. i have the same problem..... so i sneak in exercise WITH her. for example, if she is on the floor playing, lay down next to her and do some sit ups or crunches to work your belly. lay down on your back and do push ups with her (start with the bebe on your chest and lift her up and down-weeee!)(arms and upper chest). you can also lay her on your shins and pump your legs up and down- at the knee or at the hips. your baby is great weight to pick up. when im cooking or doing dishes, i put my daughter in a swing, and instead of turning it on, i push it manually with my foot (inner thingh workout). when the baby gets a little bigger, she may have fun sitting thru a 15 min workout tape with you. my oldest was in love with my yoga tape when she was 2... she had her own mat and everything. i also used to take her to the park, and do pull-ups on the monkey bars. consider investing in a jogging stroller.
there is so much you can do, without actually setting aside time for it. working out is not defined by a 30 minute, intesive "workout." good luck, i hope some of this stuff is helpful. and remember, your body is not going to be perfect for a long time after you have a child. its not like you are a supermodel for a living. dont get frustrated because you aren't able work out as regularly as you want to. it will eventually get easier. enjoy this infant time while you still have it... it goes by all too quickly.
N.