Where did extract cross-arm5vtel-cacko-linux-3.3.2-2.2.5-softloat.tar.gz ?
You must extract this file in /.
After extracting the archive in / and run runsdk.sh. runsdk.sh starts a shell with some variables set for the sdk.
The fact that when you run mkipkg you get command not found leads me to think that maybe you didn't extract the archive in /.
How did you compile gaim? you must run the configure script with some arguments like:
LDFLAGS="-Wl,-rpath-link,/opt/arm/3.3.2/armv5tel-cacko-linux/X11R6/lib" ./configure --host=armv5tel-cacko-linux --build=i686-linux --x-includes=/opt/arm/3.3.2/armv5tel-cacko-linux/X11R6/include --x-libraries=/opt/arm/3.3.2/armv5tel-cacko-linux/X11R6/lib --disable-debug --prefix=/usr/local
(you will probably have to change the path from /opt/arm/3.3.2 to something like /opt/cross/arm... if you use the latest sdk).
The crosssdk does not provides a drag and drop replacement to the gcc you have installed in you linux box, if you run "gcc -v" you'll will see that it is the compiler from you linux box that is called. Hence if you don't specify to the configure script that you want to cross-compile it will build the application for your linux pc.
The cross compiler is named armv5tel-linux-gcc (or something like that) and the configure script normally find it thanks of the --host parameter.
Somethimes configure or other makefiles/build system doesn't not find the right compiler and you need to specify environement variable like CC=armv5tel-linux-gcc etc...
Take a look at the documentation on http://www.pdaxrom.org
SDK installation and SDK tutorial. While brief it is still a good starting point