Here's a simple .bat launcher for ImgBurn. Its advantage is that, not only does it launch ImgBurn with the "/portable" parameter, but you can associate filetypes with the .bat (like *.iso, etc.) using eXpresso/C.A.F.E./Coffee and it can still portably
Title ImgBurn portable launcher
IF "%~x1" == "" (start /D "%~dp0App" ImgBurn.exe /portable) ELSE (start /D "%~dp0App" ImgBurn.exe /portable /mode write /src "%~f1")
(where ImgBurn and all its files/folders are in an "App" subfolder, to make it less likely for the user to accidentally click on the .exe instead of the .bat launcher...
You can replace the word "App" the two times it happens in the above script with your own folder name, or remove it entirely if you want to keep the .bat in the same folder as ImgBurn.)