Dave,
Some do it in one day! For a recent trip report of a one day trek, go to the website for the Bishop, California running store Sage to Summit and then go to their Message Board. Karen and Janine detail their Sept 26, 2007 North Lake South Lake day trip (via Lamarck Col). Use Google to find the Sage to Summit website.
A longer approach follows Piute Creek down to the JMT. I last did that way in 2004 with my then 12 year old daughter. We felt comfortable with 3 nights/4days. We camped at Hutchinson Meadow, Evolution Lake, and the LeConte Ranger Station. The latter two areas had many campers, especially near the Le Conte Ranger Station. We stayed away from the outlet of Evolution Lake. At the LeConte Ranger Station, a good campsite site near water, but with more solitute, is 75 yards south of the heliport there. Ask the ranger for directions.
This loop can be expanded to include many excellent side trips. I first explored the Evolution area in 1961 and am drawn back to it like a bee to honey!
Many interesting trip reports can be discovered with a little investigation on the Internet.
Enjoy your trip next summer. Jim
Last edited by Jim F; 12/31/07 10:55 PM. Reason: word change