If you use the command line in bash, you should check out the CDPATH environment variable. It'll make your life tons easier.

From the bash man pages, CDPATH is defined as:

The search path for the cd command. This is a colon-separated list of directories in which the shell looks for destination directories specified by the cd command. A sample value is “.:\~:/usr”.

In my .bashrc, I've got the following defined: CDPATH='.:..:../..:~/projects'

This allows me to just type cd app when I want to go to ~/projects/app. Another great part of it is that if I am in /var/log and want to go to /var/www I only need to type cd www. The .. in the CDPATH takes care of finding it.

The important part of it is the first one. The single period allows for cd to work normally and find directories in your current directory.