There are, at present, two versions of SATA. The older version, sometimes called SATA-150, supports transfers at speeds of up to 1.5 Gb/s. Due to the use of 8b/10b encoding, this works out to 150 MB/s, hence "SATA-150".
The newer version, sometimes called SATA-300 or (to the consternation of the SATA-IO) SATA II, supports transfers at speeds of up to 3.0 Gb/s, or 300 MB/s.
The good news first: motherboards using the older standard do support drives using the newer standard, and vice versa. If you mix and match devices this way, you will be limited to 150 MB/s. But they will work.
There are, occasionally, some complications. A handful of motherboards using older VIA chipsets reportedly have trouble auto-negotiating the transfer speed. Such motherboards are, in practice, uncommon; VIA sells few chipsets these days, and what they do sell usually end up in very-low-end motherboards. Other chipsets are rarely affected.
Many drives that use the newer standard include a jumper, which can be used to force the drive to operate at the lower speed. These jumpers are specifically intended to resolve issues with flaky motherboards. If you have a motherboard that uses the older standard, you may as well use the jumper and reduce the chance of any surprises.