Sometimes the sweetest things come in small packages. Autojump is one of those. It supercharges the good old "cd" and allows you to jump fast to the directories you mostly spend time in. After letting it to monitor your usage for a while all you need to do is to type "j dirspec" where dirspec is part of the directory path you are after, hit tab to complete the path and finally "enter" it.
I have used Autojump only for a few days but it is definitely one of those tools I wish I had known earlier about. Best of all there are prebuilt packages for many platforms so it is likely you'll be able to install it that way if you are on a Unix platform. If you spend a lot of your time in shell I highly recommend checking this little tool out. It's not much but every little thing counts.