FahMon, as you can probably guess from it's name, is a Folding At Home Monitor. It is a very useful app for anyone who runs a Folding@Home client, and can show you a great deal of info about your current work unit progress. The only problem is, while FahMon is available for Linux, it is only available as source code, and you have to compile it yourself. Don't let this scare you off though, it's a very simple process, and one this wiki will walk you through with ease. As long as you can copy/paste and navigate through Nautilus, you're good to go!
Installing FahMon
To start, open a terminal - Applications > Accessories > Terminal
Now, we need to download the latest version of FahMon:
wget -O FahMon-2.3.99.4.tar.bz2 --no-check-certificate "http://fahmon.net/downloads/current.php?linux"
Now extract the package:
tar xvf FahMon-2.3.99.4.tar.bz2
Now we'll need to install some dependencies: PLEASE NOTE: These packages will also install dependencies of their own - accept them, as well.
sudo apt-get install libwxgtk2.8-0 libwxgtk2.8-dev g++ m4 libcurl4-gnutls-dev
Change directories into the new FahMon folder:
cd FahMon-2.3.99.4
Configure:
./configure
Make the installer:
make
And finally install FahMon:
sudo make install
After this, we will need to update the cache:
sudo ldconfig
Congrats, you now have downloaded, compiled, and installed FahMon! You can now find FahMon in your menu under Applications>System Tools>FahMon, or you can start FahMon from the terminal with the command:
fahmon
Configuring FahMon
Now that we have FahMon installed, go ahead and start the program. When FahMon first starts, it will give you a notice about the project information. Read this over, as it will be good information to keep in mind. Then when you are done reading, be sure to click the 'Download Current Projects' button before clicking 'Ok'. 
Now that we finally have FahMon open, you will notice the info area is completely blank. You have to setup your folding client(s) manually for FahMon to monitor them. 
Go ahead and click on the 'Clients' menu, and select 'Add a Client'. In the small box that appears, you can enter whatever you want for 'Name' this is simply whatever you make up, and want to call your folding client. You can use Folding, CPU, F@H, etc. - whatever you want. Now for the 'Location' box we will need to enter the location for the file 'FAHlog.txt'. This is going to vary depending on which method you used to install the F@H client, so the easiest way to find the proper directory on any computer would be to open a terminal and run:
sudo find / -iname FAHlog.txt
The output of this command will be the directory we're looking for.
PLEASE NOTE: We are looking for the directory that contains the 'FAHlog.txt' file - We are not looking the 'work' folder. Be careful to select the folder that contains Fahlog.txt
After you select the proper directory, just click 'Ok' and your client info should appear in the info area. 
That's all there is to it! You can explore a bit more with options and preferences within FahMon, but I'll leave that up to you to discover for yourself.
FAQ
1) After adding my client to FahMon, it shows "Omn" under ETA, and "0.00" PPD. What is going on here?
A) This is normal. This is just how FahMon works when it's first installed or when you get a new work unit. Your folding client has to complete enough work for FahMon to be able to calculate how long it will take you to complete the work unit, as well as what your Points Per Day will be.
2) After adding my client to FahMon, it shows "N/A" under Progress and ETA. What is wrong?
A) Double-check that you entered the correct 'Location' for your client. Again, we are looking for the directory that contains the file 'FAHlog.txt' not the 'work' folder. If you do have the correct directory, make sure your folding client is working properly by running the command:
top
If you do not see "FahCore" in top, that means your folding client isn't running. It is either waiting on uploading/downloading a new work unit, or there is another reason that it is not running.
3) How do I uninstall FahMon?
A) Go through the installation instructions again - you will have to wget the package, extract it, and make sure you have the necessary dependancies installed just as you did when you installed FahMon. However, this time when you get to the installation command, instead of running:
sudo make install
Run this command:
sudo make uninstall
Voila! You're done, and you should be good to go. Also feel free to delete the FahMon package and folder that you downloaded to your home directory.
Other Issues/Questions
If you encounter any issues or have any questions, please feel free to PM, email, or find me on the forums (swoody). You can also join the Ubuntu folding team's IRC channel at #ubuntu-folding on Freenode. Also, if you'd like, you can edit the FAQ section and add your question to the list - I will answer them as quickly as I can.