Here is a list of some items that many captionists like to carry in their bags along with their computer equipment to make their jobs a little easier:

1. Extension cord with multiple plugs on the end
2. Umbrella
3. Folder for paperwork/forms required for job
4. Hand Lotion
5. Mints
6. Tissue
7. Micro Cloth (computer dust cloth – see web site below)
8. Change for vending machines
9. Tripod stand (see web site below)
10. Cross-Over Cable/Wireless Card for laptop communication
11. Disks
12. Cell Phone/Pager with silence option for messages
13. Calendar/Schedule/PDA

The Poor Man's Ergonomic Laptop Stand
Instructions on how to configure a stand to hold your laptop and use an external keyboard.
Interesting concept. 

Innovative portable laptop stands that utilize your rolling computer bag as a base.

Tripod stand and table for laptop, also other accessories such as a mini external mouse.

Portable Laptop Table with slide out mouse tray

Portadesk

Laptop Presentation Stand

Notebook Stand

Laptop Carrying Cases that Convert to mobile work stations.

Various laptop accessories such as a USB light for times when working in the dark.

Laptop Security Devices

Mini External USB Keyboard

DC/AC Power Inverter

PC Anti Theft Card

External Power Pack

Mini Optical Mouse

Aeropedic Back Pillow for use with any chair

Various types of accessories for your laptop.

Mask-Cot™ disposable covers are custom-made to fit over the soft-seal voice masks.

Micro Cloth XL dusting cloths to keep laptop screen clean and safe.