MAFFT offers a range of multiple alignment strategies, L-INS-i
(accurate; recommended for <200 sequences), FFT-NS-i (standard speed and
accuracy), FFT-NS-2 (fast; recommended for >2,000 sequences), etc.
According to BAliBASE and other benchmark tests, L-INS-i is one of the
most accurate methods currently available.

MAFFT has been described:
K. Katoh, K. Misawa, K. Kuma and T. Miyata (Nucleic Acids Res. 30:
3059-3066, 2002) MAFFT: a novel method for rapid multiple sequence
alignment based on fast Fourier transform. 

WWW: http://align.bmr.kyushu-u.ac.jp/mafft