This is a free Spider Rig for Blender 2.5 (Alpha 2)

the rig features: -IK/FK sliding -bone layer visibility UI in the properties window- -Mesh Parts Visibility UI in the properties window -Rotate the foot to pivot from the "toe" -scale the feet to rotate the knee

You can use it for whatever you want - it is totally free you can credit me if you want but no need (credit as "waylow" or "Wayne Dixon")