NAS is getting popular in office and at home, for they're small, convenient and probably suitable for small offices when they have no MIS person.
I got a chance to try out a model from Taiwan:
It features a 500MHz+ CPU with 256M memory. Obviously it's running Linux inside, you have so many features, and some of them are truely attractive.
The casing is made of metal. Installation of a SATA hard drive is simple and secure, the mounting is made with excellent fit and finish. The casing serves as a big heat sink and you can actually feel the warmth. It comes with a backup software and it works quite nice.
The performance is not great, but it's enough for normal users. If you have more than 10 active clients, I would recommend you to look for something else. Having said that, it's stable even under relatively high loading.
The bottomline is that, it's really convenient and powerful for a home user.