I have got ralink rt73 working using the serialmonkey
First of all you need a few tools - use synaptic or apt-get to install (if they are not installed on your system): gcc, make and kernel-headers (the headers must be the version which corresponds to your installed kernel. Use the command < uname -r > to see what your kernel is)
the driver (What you download is a tar.gz file which is a zipped set of source code and instructions for building the driver)
You will need to use the command line.
Copy the downloaded file to a safe place, such as the tmp folder
$ cp rt73-cvs-daily.tar.gz /tmp
change to the /tmp directory
$ cd /tmp
unzip (extract and decompress)the file
$ tar -xzvf rt73-cvs-daily.tar.gz
A new directory will be created in /tmp which contains what you need to build the driver. List the contents of the /tmp directory to see what name the directory has
It will be named something like this <rt73-cvs-2008052617>, except the numbers, corresponding to the date of the driver, will be different. Change into the new directory
$ cd <name of new directory>
List the contents to see what you have there
You should see a list something like :
CHANGELOG CVS FAQ LICENSE Module THANKS WPA_Supplicant
Change into the Module directory
$ cd Module
List the contents (as above). There should be a file named README. Read the instructions in the README file
$ less README (to exit 'less' and return to the command prompt, type 'q')
Follow the instructions in README to make and install the driver. You might want to have the instructions open in one terminal while you carry them out in another. With the instructions that need to be run as root (signified by a hash # at the start of the instruction as opposed to the dollar sign $) you will need to type 'sudo' first.
(For example: $ sudo make install)
This is an inconvenience peculiar to Ubuntu.
To use the driver I recommend the utility 'RutilT' which is provided by serialmonkey. I don't know if Ubuntu repos contain rutilt. If not , download and make the utility in the same way that you did with the rt73 driver, (except the installation instructions are in the INSTALL file, not the README file)
Good luck and ask questions if you have trouble.