joining multiple parts into one mesh

The models i am working with are in separate parts such as arms head legs and body is there anyway to merge them into one mesh

[editline]16th January 2012[/editline]

Red circles represent the parts that i want to merge them together such as hands to arms and arms to body

You can go into edit mode and select a pair of vertices, one being on the limb you want attached and the other being on the part of the body to merge at. Click ‘w’ to bring up a list of actions, and click the merge button. It’ll take awhile to do it all, but it will work.