I'm with Jinjuku. I don't think my laptop has native optical out. What are my other options?
I see two options for you
1. Get a receiver that will accept audio over HDMI
2. Get a USB soundcard that has an optical output
The first option will allow you to use a single cable to connect your laptop and take advantage of hi-def audio codecs if you get a Blu-Ray player in the future. It will also make it easier to integrate into a home theater system if you move to a larger space.
The second option will be compatible with pretty much any receiver on the market (especially the cheaper/older refurbs), but could limit the receiver's usability in the future. You would have to run a second cable for audio, however.
A quick glance around at some of the cheaper receivers seems to show that most receivers that can accept audio over HDMI will run you $60-100 more. They will be more "future-proof" which is important if you intend to expand the system over time. However, a usb audio card will run you about $30, making the difference almost negligible unless you find a killer deal on an older model.
shoponkyo.com has a deal on a refurb Onkyo 507 for $240 w/ free shipping if you register (which is free). It will accept audio over HDMI and has all the latest decoders on board, as well as Audyssey 2EQ, Dynamic EQ and Dynamic Volume (not sure about the last one). This receiver will meet all your needs and should be able to power most of the speakers on the market as long as the room isn't too large.