Originally posted by Jean Poitiers The Tamron 90:2.8 is an excellent value and great lens ... will obviously do macro, but also a short telephoto and very nice portrait if you give it enough room. I had it before I upgraded to the Pentax D-FA 100/2.8 WR.
Also, think about a tripod ... IMHO.
But buy a
good one. The cheap ones are a waste of money. If you can't afford a good one, wait until you can.
Apart from that I agree on the "lens before flash". Which lens, however, depends on what you want to achieve. Before you set out to buy anything new you really should look at what your current lenses can't do for you. If you don't feel limited, then wait until you do. (Unless you are like a lot of us and enjoy buying new toys no matter what...)
The Tamron 90 is a very nice tele macro lens, though.