People should get the capecraft mod and upload your own cape and then use it on minecraft.
Upload your cape at Minecraft Capes.com

Installation:
Step 1:Download cape craft mod
Step 2:Upload your cape at Minecraft Capes.com
Step 3:Open minecraft.jar
Step 4:Delete Meta-INF
Step 5:Put the cape craft mod files in to minecraft.jar
Step 6:Start Minecraft and HAVE FUN!!!
NOTE:Only the people who also have this mod can see your cape and you can see theirs.