Kingston 16GB microSDHC Class 10 Flash Card - Black (SDC10/16GB) w/ Adapter for $14.99 + free shipping
Pretty decent price. Note: it says 2-4 weeks for shipping, but I highly doubt they will take that long to ship.
This flash memory card from Kingston is compatible with cellphones, cameras and other devices that have microSDHC memory card slots. Its 16GB capacity allows you to store plenty of files, and you can use it to back up your phone's memory as well as to store and transfer data, audio, and video files. The card includes a full-sized SD card adapter, so you can also access your stored files as well as upload files from any device with an SD-card slot.
Memory Storage Capacity: 16GB
SD Speed Class: Class 10
Features: Speed Class 10, Write-Protect Switch
Includes: MicroSD Adapter