Several people have asked about meyer lemons so here is a little information about them from Wikipedia:
The Meyer lemon (Citrus × meyeri) is a citrus fruit, native to China, thought to be a cross between a true lemon and a mandarin orange or sweet orange. The Meyer lemon was introduced to the United States in 1908 as S.P.I. #23028, by the agricultural explorer Frank Meyer, an employee of the United States Department of Agriculture who collected a sample of the plant on a trip to China. It is commonly grown in China potted as an ornamental plant. It became popular as a food item in the United States after being rediscovered by chefs, such as Alice Waters at Chez Panisse, during the California Cuisine revolution. The Meyer lemon is also known as the Valley lemon in southern Texas due to its popularity in the Rio Grande Valley region.
Here are the ones we bought this morning at the farmer's market. It seems that this is the prime time for them here in Texas and that they are a some what freeze resistant variety of citrus. These are grown in a near by town by a man who has only one tree. I have been buying from him for several weeks now. I plan to buy my own tree and keep in in a large pot.