I travel alot and often find it difficult to get work outs of any kind when I am gone. I went to a fitness store and talked to someone there about my my situation. She suggested exercise tubes. The ones I bought were by Spri Products. There were cheap, and VERY effective. (there's a little booklet you can buy too that explains more movements than what are included on the tubes package)
For abbs...I found an acticle in Women' World several months ago about abb exercises. They are fabulous! I liked it so much I took the magazine to kinko's photocopied the page and had it laminated! It goes with me on every trip I make....along with my Spri Tubes.