Hello,
I seem to have forgotten to install SuPHP on one of my servers and would like to install it now. I was wondering if there is a way to do this without rebuilding Apache2. I know this can be done with ioncube using the /scripts/ command, but was wondering if it exists for SuPHP?

If it is compiled into apache you can do:

/usr/local/cpanel/bin/rebuild_phpconf 5 none suphp 1

Which will enable suphp for php 5.

If its not compiled, you will need to compile it with easyapache.

Thanks,
I guess I will need to resort to easy apache

you have to recompile the apache with suphp using easyapache

Easyapache is the best way to do it.