Hi all, I have a bit of a love affair with my mini (Core Duo 1.6Ghz 1G from 2006). It's such a tiny, power-efficient, and reasonably powerful computer, so I was interested in what others were using theirs for apart from as a general desktop computer. hopefully my story below might give others some inspiration or maybe get some interesting stories about how minis can be used.
Mine's been in daily use ever since I bought it nearly 2 years ago (from some guy who sold it on eBay because he wanted to upgrade to a iMac straight after he got it..duh). I can almost say I actually use the little thing more overall than I use my 24" iMac (that's a bit sad). It's still got an 80Gb HD in it but I've upped the memory to 1.5Gb and have a 500Gb external USB drive attached). Oh and I upgraded to Leopard. It sits in my entertainment unit in my lounge, connected to the LAN and doing lots and lots of interesting things:
So here it is in my entertainment unit. We've got no VCR, no DVD player, no CD player. All I have is the mini, a satellite decoder, and a Wii, connected to the TV and my Denon AVR.. While I'm sort of an audiophile (check out the chunky center speaker below) and can tell the difference between my Aarons and a set of say, Bose speakers, I can't see why audiophiles get their knickers in a twist over certain brands of CD players sounding different when they are connected via Optical to their AVRs. I mean, shit, it's the same series of bits whether it comes from a computer, a CD player, or whatever right??!
Obviously I use Front Row for music and to watch movies, etc. Here's my 32" LCD with the mini below and the TV and the Unfortunately my audiophillic beliefs lean towards the non-miniaturisation of speakers for best sound reproduction and with my budget only extending to a 32" the whole set up kinda looks a bit daft. Also re having a 32" LCD - the max res on it is 1360x768 which means that HD channels aren't REALLY HD - I wonder if the mini has enough grunt to drive something that's REAL 1080p/i?
Naturally the mac outputs optical to the AVR and has no problems at all outputting all manner of audio - PCM, DTS, Dolby digital etc. Here the AVR is receiving DTS from the mini which is playing a DTS track in iTunes.
Next up, when the mood to watch mind-numbing crap takes me or anybody else, EyeTV starts up and we have FTA DTV. You can hit the MENU button on the Apple Remote for Front Row or hold it for EyeTV controls (PVR, change channel etc). Here you can see someone's mouth as they consume large amounts of uhh, pork ribs.
Onto more geekier matters the mini is also being used as a PABX since I usually have it on most of the time anyway. I have it running VMWare Fusion and currently its running PBX In A Flash from NerdVittles. We've got about 6 SIP clients around the house and this acts as a central switch with voicemail, trunks to friends and so on.
The mini also makes for a great Torrent box with Transmission and when I'm bored enough I'll fire up MAME OS X on it and play a round of something (of course all the games I have on there are public domain or I have a copy of the game boards!

) It also runs Streamripper X some of the time, acts as a file server to the other computers in the household, and I can VNC/Screenshare into it from work/my iMac/iPhone/your mums computer whichis pretty handy.
Finally here's the mini running MAME OS X and EyeTV (on 7HD) side by side. Tekken 3 runs like a dog, funny that. iStat says the CPU is maxing out. The purpose of this is that I had an energy meter connected to the mini. While it was maxing out both cores, it was pulling an average of about 52W, which is pretty damn decent in my books. When it idles it sits around 25W.
Alright so that's my story kthxbi!