Google Desktop Search is a nice utility, and its support for indexing AIM conversations has saved me many times when I have had to remember some obscure detail that someone metioned to me in an IM several weeks before. Unfortunately, it doesn't support AIM Triton yet, but getting it working is not too difficult. If you're handy with a hex editor, you can follow the steps below. Otherwise, you can skip to the end and just download the file you need.
1. Shut down GDS, from the tray icon.
2. Find GoogleDesktopNetwork2.dll; for me, this file was in the "C:\Program Files\Google\Google Desktop Search" folder.
3. Make a backup of this file, in case you make a mistake.
4. Open GoogleDesktopNetwork2.dll in your favorite hex editor.
5. Scroll down to approximately offset 0x1A000, or search for "aim.exe"
6. You will see a list of EXEs such as waol.exe, opera.exe,
netscape.exe, msn6.exe. Each name will be in Unicode format, meaning
each character is 2 bytes, with the first character being a NUL (00).
7. Pick one of the EXEs that you do not use; "msn6.exe" is a good
choice because it is the same size as "aim6.exe". (To be fair, I will
note that "waol.exe" is also a good choice.)
8. Replace the EXE name that you have chosen with aim6.exe. If you
chose a name that was longer than 4 characters, you will need to
replace the remaining characters with NUL bytes.
9. Save your changes.
10. Restart GDS.
11. Restart AIM Triton.
If you don't want to go through all this trouble yourself, and you are
using the version "Google Desktop 20050818-en", you can use the GoogleDesktopNetwork2.dll that I modified and skip steps 4-8.