Thoughts on leasing a car rather than buying?

Honda is offering some very cheap deals for leasing new Honda Fits – around $175 /month. I don’t know much about leasing and am wondering what the advantages/disadvantages are of leasing a car over buying one. Anyone have experience with leasing? I’m trying to figure out the most cost effective options – started out thinking of buying a cheap used car but began to realize I might have to sink a lot of money into repairs, so am considering other options.