Since gaim has been renamed to pidgin and upgraded version for a long time, I couldn't endure any longer, so I modified GaimPortable by myself.
First, change all the path and file names including "gaim" to "pidgin", open the source file "PidginPortable.nsi" and do the same change. Note that the names in the source file are case sensive. Pidgin uses a new environment variable named "PURPLEHOME" instead of the old one named "GAIMHOME", so the replacement should also be made in the source file "PidginPortable.nsi".
If you want to keep your old game settings, just rename the profile folder name from ".game" to ".purple" and copy it to "PidginPortable\Data\settings".
By the way, I found a funny thing: "HKEY_CURRENT_USER\Software\pidgin\Installer Language" registry value seemes to control the language of pidgin's interface. I first installed pidgin using Chinese interface, the value is "2052". After I changed it to "1033", the interface changed to English.
See the beta forums. It's been in testing for a while. A 2.1 pre-release was recently posted. It's a bit complicated as we had to ensure that Aspell, OTR, Gaim-Encryption and other important bits work. Also, the language setting is handled by the launcher using an environment variable.
Sometimes, the impossible can become possible, if you're awesome!