Handy tip for travellers:

If you need to wear a shirt to dinner, but everything's crumpled, the iron service costs to much and the hotel refuses to give you an iron then here's a little trick to make you look presentable:

Most hotel rooms have a hair-dryer. Put the shirt on or put it on a hanger, and run the hair-dryer slowly but smoothly over the shirt. If it's on you, your own body heat will contribute to smoothing the wrinkles, but after a few minutes the shirt should be presentable.

This doesn't work on all shirts - typically a shirt that's easy to iron will respond well to this treatment, but some shirts refuse all de-wrinkling.