Please! I need a good flash for my Canon Digital Rebel XT. I take lots of pictures indoors at basketball games or school plays and other functions. The camera flash does just not provide enough power. I'd love to have the Canon high end flash but they are just so expensive. Is there another brand...

If you are looking to get the most for your money, Sigma EF 500DG Super is an excellent choice. I using this one myself, and there is nothing that I can pick on. The flash is versatile, easy to use, intelligent, and very good in multi-slave configurations.