I personally use a Black Rapid RS-7 strap. see: blackrapid.com
Another great strap to check out is the Carry Speed line. see: carryspeed.ccom
The Black Rapid attaches using a bolt that screws into the tripod hole on the base of the camera, grip, or lens collar. The bolt has a swivel and slides along the strap.
The Carry Speed actually attaches using a plate with an offset ball-head. There's a ballhead connector that slides along the strap. The plate has 1/4" 20 tripod holes in it so you can attach your tripod mounting plate to their plate. They also have an optional plate which is an arca-swiss dovetail plate but still has the ballhead off to the side and still has 1/4" 20 holes.
A friend of mine bought the Carry Speed (remember, I have the Black Rapid) and I really liked the design. They have similar designs except that the Carry Speed always has an arca-swiss tripod plate on the bottom of the camera and the connector is offset to one corner of the plate. I've been thinking about switching over because all my tripod heads have arca-swiss style dovetail saddles.