Texpac by David Maziarka is an application that will pack gfx files up into one image. It can be used for sprites, textures, animation strips and bitmap fonts and is often referred as a texture packer or sprite atlas.  There are 2 resulting in files, one .png and one .pac file that contains the coordinates of each packed image.

Features and Benefits:

• Keeping your gfx in a pac means you only have to incbin one file. this can help you to be more organized.
• Bitmap fonts.
• Basic experimental graphic filters
• Loads png, jpeg and bmp.
• Fully alpha transparency capable.
• Fonts can be spaced such as to give room for modification in a paint program.
• You can create spacer rects. useful when creating an image strip for a toolbar in MaxGUI
• Save the project you’re working on for later modification.
• Easy to use export file
• BlitzMax module, load and draw the images and the fonts.
• Monkey import file for draw of images and fonts
• Performance, this module’s draw routines can be 2x faster than the Blitz DrawImage on many cards.
• The font drawing can is up 2x faster on almost all cards.

Here is a short little tutorial to get you started.