OWC and NewerTech have afforadable 8GB RAM upgrades for your

Apple’s new unibody Mac mini has the removable bottom cover for easy access to its memory modules. In keeping with this Other World Computing (OWC) and Newer Technologies have released affordable Mac mini memory modules with your name on them. Alternatively, you can have Apple outfit your Mac mini with their overpriced modules lacking full lifetime warranties and money back guarantees. iFixIt’s Mac mini teardown has taught us that the machine’s removable bottom cover provides access to a pair of CL7 204-pin SO-DIMM slots that support up to 8GB, a major step up from 2GB on the previous generation.
OWC’s memory upgrade kit comes in two flavors: one or two 4GB PC-8500 DDR3 1066MHz memory modules priced at $150 and $296, respectively. The comparable modules from NewerTech cost $135 or $250. If you opt for either firm’s dual 4GB modules (for 8GB total RAM), you’ll save up to 41 percent and 50 percent, respectively, compared to Apple’s pricey 4GB modules.

Note that a single 4GB module replaces one of the two factory installed 1GB modules in your Mac mini. As a result, you end up with 5GB or 6GB total RAM, depending on whether you bought a $700 Mac mini with 2GB RAM or a $1000 Mac mini server fitted with 4GB RAM. Both firm’s kits are compatible with the unibody Mac mini 2.4GHz, 2.66 GHz, and 2.66 GHz mini Server models. OWC also offers a trade-in rebate program for your factory standard memory modules.