@JC_Leon - any decent graphics app will do. I use Paint Shop Pro, but you could use Photoshop or Paint.NET or whatever.
Alternatively, there's a little app called "Fusion Spritesheet Exporter", which you could use (you'll still need to arrange all the sprites neatly, I believe).
http://complex.softwares.free.fr/pro...xample_img.jpg
Download:
http://complex.softwares.free.fr/dow...t_Exporter.rar
@AyreGuitar - I haven't tried Photobucket recently, but it used to be pretty bad. Has it got better? I wonder if Skydrive allows image hotlinking..?