I've referenced WalMart because of ease of use. You are responsible for your own shopping.
- Webcam - $15
- Microphone - $10
- Headset w/ Microphone - $15
- Wireless Mouse - $15
- Wireless Keyboard & Mouse - $20 - $30
- Card Reader - $10
- Speakers - $15
- Power Surge Strip - under $10
- USB Hub (4 port) - $10 - $15
- Wireless Presenter Mouse - $30
***
Really cool USB accessories from thinkgeek.com (once again, shop responsibly)
- USB Flexible Light - $10
- USB Lava Lamp - under $20 (depending on model) http://www.vat19.com/dvds/usb-lava-lamp.cfm
- USB Rocket Launcher - $30 - http://www.thinkgeek.com/computing/accessories/8a0f/
- USB SnowBot - $8 - http://www.thinkgeek.com/computing/accessories/854a/
You can really get geeked out for relatively cheap. Think of it this way, these items replace the "Office Accessories" such as the "putting course pen holder" and "metal spheres on a string" dealio.