I used to run Trillian from my USB drive under U3.  Then I got a laptop with
a built-in SD card reader, so I wanted to run all my apps without having a USB
drive sticking out the side of the computer.  As far as I know, you can’t get
a U3 SD card (wouldn’t make sense at all).  Also, there is not a “portable” version
of Trillian other than U3.  I found a way to use the U3 version of Trillian
as a truly portable application.

Trillian U3 on a standard
USB drive

Instructions copied here for convenience sake:

First you will need access to a U3 drive.

1. Download and install Trillian for U3 on to the U3 Drive.
2. Copy the U3P file from the system\apps folder to a temporary location.
       i.e. U:\System\Apps\58EA136C-7E57-4416-B59E-394C46DD505B\Trillian-v3.11-b1028.u3p
3. Rename the u3p file you just copied to a zip file. i.e. Trillian-v3.11-b1028.zip
4. You can now uninstall Trillian from the U3 drive if you wish.
5. Extract the zip file.
6. Copy the Data\Users folder to the Host folder
7. Delete the Data folder, delete the Exec folder, delete the manifest folder
   Optional: Rename the host folder to Trillian
8. Copy to your usb drive
9. Run Trillian