If you're sending large (over 1 GB) files around your network, gigabit is significantly faster. I backup my Winders boxes over my network to my Linux server. I run full backups each time, so they're 8-24 GB each. The time was cut about in half when switching to Gb switches and Gb cards in the PCs.

I use NetGear GS108 switches. I think they can run all eight ports at full speed, but I can't remember for sure. They're on sale at my favorite ovoid-shaped online retailer for $32.74 with free shipping. $4.09 per port is a pretty good price.

There used to be a "puffy capacitor" problem on the GS108, but I think it's fixed on the newer models.