Buy.com has Kingston 8GB microSDHC Card - (Class 4) - SDC4/8GB for $18.95 + free shipping.
Features
Compliant — with the SD Specification Version 2.00
Versatile — when combined with the adapter, can be used as a full-size SDHC card
Compatible — with microSDHC host devices; not compatible with standard microSD-enabled device/readers
File Format — FAT 32
Tech Specs
Capacity — 8GB
Dimensions — 0.43 x 0.59 x 0.039 ( 11mm x 15mm x 1mm)
High-Speed Class Rating Class 4: 4MB/sec. minimum data transfer rate
Operating temperatures — -13°F to 185°F (-25°C to 85°C)
Storage temperatures — -40°F to 185°F (-40°C to 85°C)
Weight — .05 oz (1.4g)
Kingston 8GB microSDHC Card - (Class 4) - SDC4/8GB $18.95 FS 
