<h1>Python 84</h1>

Requires input in brackets instead of parenthesis.

    a=input();r=[]
    while a:
     n=a.pop(0);m=10-n
     if m in a:a.remove(m);r+=[(n,m)]
    print r

For roughly the same answer golfed better see [Daniel's answer](https://codegolf.stackexchange.com/a/8999/2621).