USB Scanner Driver Version 0.4.5-3 . This should be a drop in replacement for 2.4.0 kernels. This version is not yet in the kernel but should be soon. USB Scanner Driver Version 0.4.3.1 . Note that this version adresses the issues surrounding Epson scanners.
More information is available via the news page.
Patch for linux-2.3.26 using version 0.3.2 . Patch for linux-2.3.25 using version 0.3.1 . These are fairly old patches for older development kernels. An updated patch finally made it into the kernel source sometime around linux-2.3.38 or so. Patch for linux-2.3.45 using version 0.4.1 .