Go2Africa have this interactive map that is based on flash technology. Right click on a link (town, national park, etc.) to open the contextual menu from which you can undertake several different activities like zooming or looping. The only regret is that zooming, for example, does not actually provide more detail. Left clicking on a link brings up a description of the link. Have fun.
Other maps of Lesotho:
1/. Lonely Planet
2/. Yahoo Travel
3/. About's Blank Outline Map of Lesotho
5/. Maptown, if you want to buy a map.