Vacation training tips?

I just do what I can.  Basically just focus on running since that's easy to pack for.  That, and look for a stationary bike at the hotel or local gym

I think the most important thing is to do something to keep your aerobic fitness up, it doesn't matter what.  I don't think you are going to lose any/much bike fitness if you don't ride for a week but make up for it with run/swim time.

I think for the short time of a vacation, just getting most of your hours in is the most important thing, not what you are doing.  I would skip the bike unless it's convenient and just run.  I usually skip the swim as well unless I am vacationing next to an ocean!  I don't get to do ocean swims that much, so I would jump at the chance.

Ditto to the above.

I try to remember that I am on vacation.  I try not to spoil it for everyone else by insisting on training all the time.  If you go out running or biking, don't get lost and do carry some id with you.  Especially an id that will tell them what hotel you're staying in.  Also make sure the people with you have a good idea of where you went in case you don't show back up.

You have about 72 hours between work outs before you start losing strength.  You could almost survive the gap by going to a fitness center and running on the treadmill, riding an Exercycle and swimming at a pool in the middle of the vacation.

If you've been training a lot and run the risk of exercise withdrawal it may be in the best interest of everyone around to let you train for 30 minutes a day even though you're on vacation.  I suffer particularly from this.