I just bought a Joy Mangano My Little Steamer and it works extremely well.
I steamed the wrinkles out of a cotton tuxedo shirt that was straight from the package and had some deep creases. It wasn't as crisp as if an iron had touched it but it was good enough for suitcase crushes.
Best part about this little steamer is that it's basically a tea kettle with attachments. It will do double duty for a fast cup of coffee or tea if you bring tea/coffee bags with you.
Only thing I don't like is that it's a little bulky and will take up more suitcase room than I'm comfortible giving up.