Synology Disk Station DS-107+
The Synology DS107+ is the most sophisticated NAS device we've tested to date. Its more advanced features require some networking know-how, but the included software and Web interface go a long way in helping you tackle the various offerings. You can't beat all the features you get for the price.
http://reviews.cnet.com/Synology_Disk_Station_DS_107/4505-3382_7-32987447.html?subj=fdba&part=rss&tag=MR_Networking+and+Wi-Fi