Baiters have their own preferences as to what programs to use.
Below is a list of the ones I use, along with the reasons why.

1. Mozilla Firefox
Add a few extensions and it's perfect for baiting.
I use adblock and noscript for checking out websites,
Gmail notifier to watch my Gmail accounts,
EXIF viewer to see the hidden information in photos
and downloadhelper to make copies of my Youtube videos.

2. Trillian
The perfect multi IM program.
Allows you to run several (or several dozen) accounts at once.
Works with AIM, YIM, MSN and ICQ

3. Yahoo Instant Messenger
I switch to this when I need to do a cam session with a scammer.

4. Irfanview
Free software to view photos and - once the plugins are installed -
 view EXIF data.

5. Manycam
Lets me create a "fake webcam" to use on IM scammers.

6. Super Screen Recorder
Captures all those scammer webcams you see posted.

7. Audacity
A good, free audio utility - used a lot to make the radio shows.

8. Windows Movie Maker
For the Youtube videos.