The Intel Mac Mini comes standard with two 256MB SODIMMS. You can install up to 2GBs of memory by using two 1GB SODIMMs.

Standard Memory
512MB Removable
Maximum Memory
Memory Expansion (No. of sockets)
2 Expansion Sockets
Memory Expansion
Install 1 at a time
Memory Sizes
512MB / 1GB
Memory Speed (Type)
PC2-5300 DDR2-667