I travel semi-regularly for work and have to stay in hotels. I've often used resistance bands, but have recently started going to gyms while away. Most hotel gyms are rubbish, try and find one that has an affiliation with a local gym, you'll get free entry as a hotel guest.
Resistance bands are quite cheap at around $30 for a pack of 3. They're pretty good, if you double them up (use 2 strong bands at the same time) you can get a decent amount of resistance. Loop them through a roll of duct tape and place the tape over the top of the bathroom door, shut the door, the tape anchors the band in place. You can sit on the floor and do lat pulldowns. If you anchor the band at the side of the door you can do seated rows.
You can do some good shoulder, bicep, tricep exercises with them, also squats. Youtube has heaps of videos of different exercises you can do with them. I didn't find them great for chest work, but you can do pushups with feet elevated.
Edit: sorry just read your other post about not being able to got to a gym, forget what I said about that. Invest in the resistance bands, they'll make a nice change, a chance to mix it up for a slightly higher rep workout.