I got a Mac Mini (Core Duo 1.66, 512 ram, 60GB) about 3 months ago and had it collocated in a data center. At first I just wanted it to be a web server but it has surprised me how many things I can do with it. Its primary purpose was to host some personal sites, as well as friend/family sites and blogs and what not. I then added postfix and dovecot IMAP and have used it for personal email now. Having full control of the mail server has me 100% spam free so far. I also use it for offsite backup of important files from my computers. Couple that with Amazon's S3 service and this app called JungleDisk (mounts a remote disk on your computer which is stored in S3) and I have another layer of backup there for pennies a month. Of course this is all the standard stuff you'd imagine you can do, so here's some of the cooler stuff I discovered. - I like .Mac services a lot, but find .Mac a bit too expensive. Using WebDav with Apache, you can basically get a service similar to iDisk set up. There's a tutorial floating out there on how to have your own emulated iDisk service and I gave that a try for a while. Worked well, but it was quite a hack and I am happy enough with standard WebDav access. The Apple/Windows file sharing service (afp or smb) is also very useful in this regard. Another .Mac-like feature is to use iWeb to publish pages similar to .Mac's Homepage with ease. - I found out about Dot.Tunes (remote iTunes library access) recently and had an external drive added to the mini with all my media on it. I now have access to all my music/tv shows/movies anywhere I go. I also added this iPhone plugin and can listen to anything, anywhere without worrying about the limited iPhone space. - Sometimes while traveling outside the country, I have trouble accessing some sites because they restrict access to the USA. One example is online shopping, where my IP doesn't match the shipping/billing address so the site returns an error. Also, sites like Megaupload.com for example don't let you download files for free out of the country which can be a hassle sometimes. So, using Remote Desktop or a VNC client, I use Safari on the Mac Mini to accomplish these tasks and it works like a charm. In terms of reliability and performance, I am very impressed with the Mini. My current uptime is - 20:58 up 47 days, 7:26, 2 users, load averages: 0.12 0.05 0.03 - Haven't had a complain from anyone about downtime in any service really. Overall one of the best Apple purchases made so far. The Mini really is a beast inside.