By late February/early March spring is often well underway. Have you done a couple of the obvious ones, like Wildrose and Corkscrew? Finding the right canyon to begin the actual climb of Corkscrew is a bit tricky, but after that there's usually a defined treadway to the top.
A bit closer to my home, there are some local hikes like Jenkins, Boulder, Deer/Chukar and even Owens - all in the southern Sierra - which are usually snow-free by that time.
Another interesting hike in the Panamints is Surprise Canyon. It's a 4K' hike up to Panamint City, an old mining camp. The lower part is a bit tricky as the brush is very thick, but get an early start and take your time. Lots of wildlife in that canyon, and you can overnight in one of the old cabins as well.
Last edited by KevinR; 11/17/09 07:52 AM.