If you do much work with Perl and web applications then you likely spend a lot of time on Linux. If you're serious about Linux then you probably spend a lot of time typing obscure and arcane command snippets into a terminal window. If you don't love the command line, you soon learn to at least live with it.
SSH is a good way to connect to a remote Linux server and get command line access to it securely, which is all well and good, but if you're sitting at a Mac, surrounded by the shiny UI candy that Macs are famous for, you start to miss the little things: like a mouse and a cursor, for example.
I recently came across a bit of Linux technology that can only be called "cool." It's called SSHFS and it essentially allows you to connect a remote filesystem onto your local filesystem via SSH. What that means is if you can get to a server via SSH, you can use SSHFS to make it appear (and function) as if that remote server were just another directory on your computer. Yes, that most certainly is cool.
Now SSHFS has come to the land of Mac. The implications of this are amazing. It means you can use all your sweet Macintosh applications, like Photoshop and TextMate to work directly on files that exist on remote Linux web servers. This is a huge improvement over having to download an image, edit it, then upload it again. With SSHFS you can simply open the image and work on it. In every way the remote file behaves as if it were sitting on your own hard drive. In fact, I'm editing this very file via SSHFS right now!
SSHFS has long been available for Linux clients, but can now be installed on a Mac client as well. The SSHFS app requires that you install MacFUSE Core first; both are available on the macfuse project page over at Google code.