You can install nvidia driver without reboot.
Requirements:
0: Module unloading is compiled into the kernel.
Loadable module support --->Module unloading
1: init 3, you do not boot-up to Xwindows.
2: agpart - compiled as module, this seems to be a requirement with 71** drivers.
edited:
"3: I guess it is quite obvious you need root access.
"
Steps:
1. Download latest nvidia driver.
2. modprobe -r nividia
3. cd /path/to/NVIDIA-driver
4. sh NVIDIA-driver and follow through the normal compilation/installation procedure
5. startx
6. in a terminal, nvidia-settings &
The NVIDIA X Server Settings window will appear and you can see the NVIDIA Driver Version: 1.0-7174(latest)
Hope this helps.
Edited:
Works fine with Slackware-currrent, 2.6.11.6 kernel.
Edited again:
Beat the hell out of windoze, huh.. who says installing new driver needs rebooting?