should I use wxWidgets or is GTK+ enough?

[bob self <bobself charter net>]

I write windows programs but would like to start making my apps 
cross-platform. Originally I thought that wxWidgets was the way to go,
but I wanted to consider alternatives before I make the switch. Could I 
accomplish mostly the same thing by using GTK+ instead? WxWidgets uses gtk,
I've heard, so maybe it's just another (unnecessary?) layer.

thanks,
Bob