I bought a 1.83 GHz C2D A1176 Mac Mini (2007) for $150 on eBay. I bought 4GB RAM for $45, it already had Lion installed. I bought a 500GB 5400RPM HD for $50. I bought an OWC SSD for $70 and a caddy $50 Total Package: $365 but the SSD and 500GB hard drive will step this machine up for a while. The smaller of the two new Mac Minis is $600. I have another mac mini A1176 Core Duo. I upgraded the processor with a T7600 for $30 (Amazon) and formatted the 80GB drive and installed Snow Leopard which I have already. I did buy a new optical Superdrive ($50) because I want to play DVDs on the beast. I left the original 2GB memory in it because I don't want to risk the firmware upgrade in case I end up with a brick. So $80 and I have a fairly decent upgrade.

Yes, you can Yes, you can upgrade the core duo or core solo processors (Checkout the iFixiT videos). Go slow because it's tricky getting the heat sink off the processor and back on with the four plastic posts and springs holding down the heat sink. It's easy to lose springs. The plastic barbs break off easily so you will want to get plastic screws and bolts ahead of time to replace the brittle posts that you break (I broke two of the four). The heat sink is also "welded" on to the old processor so be patient while you persuade the two to break apart. Also, the old thermal paste has to be worked off the new processor and heat sink a number of times using ArticClear remover and purifier. You can then add fresh thermal paste to the replacement processor (thin layer). Heat Sink Check the orientation of the heat sink also because the new processor is not oriented the same way as the original and if you use the outline of the old processor on the heat sink as a guide you will have to take the heat sink back off...

I updated a Mac Mini A1176 1.66 GHz Core Duo with the following: 500GB Seagate Momentus (Amazon) 2.33 GHz T7600 processor (Amazon) 4GB RAM (3GB usable) New Optical drive (OWC) New PRAM battery I found that using one of the old 1GB memory sticks with a new 2GB stick did not work. I had to remove the old stick for the machine to come up. I ordered another new 2GB stick so that I could use 3GB RAM when operating with Lion OS. I know I can update the "bios" to 2,1 and also get Lion operational by deleting the hidden ."pram" file. I broke one of the plastic post retaining thingys while removing the processor heat sink but fortunately I ordered some replacement plastic screws ahead of time. Also, I bought the two small bottles of stuff to remove the old thermal paste and I found I had to work away at it several times using a credit card to get the paste of the heat sink and the processor. Also, it was difficult getting the heat sink off the processor after removing the pins. The heat sink was "welded" to the old...