Fry's Electronics offers the Hornettek Transporter 2.5"/3.5" USB to SATA Adapter, model no. HT-TC101U2J, for $5.95. Opt for in-store pickup to avoid the $2.99 shipping charge. That's $12 off list and tied with last week's mention as the lowest price we could find. It features transfer speeds of up to 480Mb/s.
Update: Specs corrected.