Nvclock allows you to tweak your Nvidia card
under Linux and FreeBSD. It features overclocking, hardware monitoring, tweaking of OpenGL settings, and much more.
Information regarding Project Releases and Project Resources. Note that the information here is a quote from Freecode.com page, and the downloads themselves may not be hosted on OSDN.
This version adds Geforce8 support, contains a rewritten low-level Geforce6/7 overclocking backend [experimental], and adds BIOS PLL table parsing for Geforce6/7/8 cards. It has fan speed adjustments for 8800 cards equipped with ADT7473 chips, support for additional Geforce7 AGP cards, and support for more NV-CONTROL OpenGL settings in GTK. It fixes many bugs, including pipeline and Quadro faking issues.