There are literally hundreds of utility programs, the majority of which were produced by Free Software Foundation staff and volunteers. Linux is testimony to the idea that freely distributable software can be usable, and of high quality. Linux would have never happened if it had not been free, and had there not been the GNU utilities to complete the picture. You can help further the cause of the FSF in a number of ways, both directly and indirectly. If you are a programmer or a writer, or both, the FSF has software and documentation that needs to be written.
Serious volunteers are always welcome.
If you want to help support the FSF monetarily, you can do that too. The FSF sells tape and CD-ROMs with their software on it. You probably already have most of the software, but you may wish to have the printed documentation that goes with it. The GNU manuals are nicely printed and bound, and are not expensive. Buying software and manuals directly contributes to the production of more, high-quality, free software.