In Snow Leopard, you can find ⌘ under Symbols>Technical Symbols in Character Viewer when you select the By Category tab. It's probably the same in Lion.

Jon

macOS 11.7.10, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P600, Photoshop CC, Lightroom CC, MS Office 365