Amazon offers the Corsair Force GT 120GB Serial ATA 6Gbp/s 2.5" Solid State Disk (SSD), model no. CSSD-F120GBGT-BK, for $179.99. With free shipping, that's $1.50/GB and the lowest total price we could find by $35 (outside of the below rebate offer). This drive features read speeds of up to 555MB/s and write speeds of up to 515MB/s.

newegg has it for the same price after this $30 mail-in rebate. Rebate expires September 26.