WOuldn't use laptop speakers, but a decent powered speaker should suffice fine. If you can get one with a built in mixer on the back would be even better. Carvin actually makes a decent one.
http://www.carvin.com/products/single.p ... 0&CID=SYS1
Has a built in 4 channel mixer & also built in digital effects for vocal (the 400D model). 100 watts & battery operational as well!