With making programs from source sometimes it's nessiciary to specify in more then one place the installation directory.
Like you go:
configure --prefix=/home/goi
make
make prefix=/home/goi install
Otherwise I am not to sure. Check out Freshmeat I guess.
Lots of times for simpler programs I'll just go:
./configure
make
and then once that is done I find the executable, or the entire folder, or whatever and copy it to my ~/apps directory.
Also if the client has libraries that it has to link to normally, it's configure script may have a option to compile a staticly compiled version. Generally ./configure --help will show you options, although you may have to read the configure script with a text editor to see all the options. Then you can copy the resulting binary and configuration files to were ever you want.
Another option is to find pre-compiled binaries for your system. Debian files and Slackware files are pretty much just tarballs you can extract just like everything else with a extra directory containing special information (like package discription and install/uninstall scripts) that gets recorded then deleted at install time. If your using a RPM platform then you can use a rpm2cpio command to change it over to cpio and from that extract it to a tmp directory and then copy it to your home directory how you want it. Probably won't help, though, if you have a bunch of dynamicly linked libraries that you have to install in their proper directories for it to work.
Otherwise I don't have any advice on a simple IRC client you can install and have it be easy on yourself.
Maybe check out ircII or irssi.
edit:
this guy mentions installing it in your home directory.