Interesting that you said you don't have time to run--I run for exercise b/c it seems like far the most efficient way to do it (just run out of your house, not need to go to gym, etc.); I don't particularly enjoy it. MP3 player makes it tolerable.

Jump rope. 10 min of that is equal to 30 min of joggin, atleast in the cadio department.

have you tried crossfit?

http://www.crossfit.com

a lot of their workouts require nothing more than a pullup bar and some space for squats/pushups. however it's most useful for training power and power-endurance rather than extensive cardio endurance. it also has a cult factor to it, but it's very easy to modify their workouts to suit your needs.

you might also be interested in kettlebell training. again, it's best for power and power-endurance, but given that you don't much like running/biking/swimming, it's definitely a good option. swings, snatches, and clean & presses are great exercises.

I know you're just looking for ideas, but I can't help but ask what your goals are? I sort of feel like lots of people spend about an hour a day doing junk workouts, where significant gains can be made with the right 20-30 minute workouts at high effort. you won't build much long-term endurance, but your lactic acid tolerance and aerobic capacity will shoot way up.

I am also very vigilant in using clear and obvious hand signals. The middle one worked perfectly well this morning in Harvard Square.

just a hunch, but are you talking about the fork by the EMS, where you bear left to get to Central square? I got denied by a pretty big truck this morning, had to go around.

also, it really depends on where you live. according to a friend of mine who is a courier in NYC, drivers actually will try to kill him. so uh, yeah, just be careful. eye contact helps. most people have trouble killing people they make eye contact with.

IMO, running is one of the most efficient means of cardio in terms of time (much more so than biking). i'd run and swim while i was doing cardio more regularly. i just run for about 30-45 min, with the single goal of maintaining my target heart rate for at least 30. i never really kept careful track of the distance, but it's around 3-4mi or so. the swimming is just more of a cardio workout targeted toward surfing (i hate it; it's boring as hell, but i find it to be one of the most exhausting all around cardio activities).

Please, note, this is NOT about whether cardio will help you train for climbing.

I believe that cardio is important for other reasons, and more specifically, believe that *I* should be doing it, but I am having trouble coming up with something that i would actually like doing.

Running-- probably isn't going to happen b/c I hate running, and b/c I just don't have time to go for a run.

Biking to work would be nice, but lack of bike lines scares me, and the fact that I have to either pick up or drop off the kids prevents me from doing it. I tried a spinning class, but all I could think of, the entire hour, was B_O_R_I_N_G.

All exercise machines. like treadmills, fall into the B_O_R_I_N_G category, as well.

Swimming-- I like it, but I hate chlorine in the pool, and logistically it is too much of a hassle, though doable, I suppose, as a lunch break at work sort of thing.

Aerobics... I guess I could try it again, It's been many, many years. LOL.

Why, oh why doesn't yoga qualify as cardio? Maybe I could convince myself that it does, after all, if it is power yoga?

x-c skiing? Rollerblading? (those two are supposedly good cross-training for each other)

I'm sure someone here on rc will claim that yoga is good for cardiovascular fitness. After all, multiple people have claimed, quite seriously, that playing guitar, piano, and drums are all good for climbing fitness.