I just got my e20 agfa snapscan usb to work on linux (Mandrake 8.1) following the instructions in URLs
Snapscan on Source forge
Henrik's home page

I got the firmware from the agfa install disk (it was called snape20.bin and I also found it in windows/system on my windows partition after installing on windows).

The output from agfafirm -v /dev/usbscanner snape20.bin was

Firmware Information (from file)
        Chip:          7107U
        Vendor:        AGFA
        Version:       0.62
        Model:         SNAPSCAN_e20
        Firmware date: Tue Nov 14 2000 14:14
        Size:          30149

Uploading new firmware...
Done!
Scanner Information (from scanner)
        Vendor:        AGFA
        Version:       0062
        Model:         SNAPSCAN e20
        Firmware date: Tue Nov 14 2000 14:14


My system is running Linux Mandrake 8.1 and the scanner seems to work fine using the firmware supplied on the CD coming with the scanner (snape20.bin). Without the firmware upload xsane does not find the scanner.
The scanner works without firmware upload if it has been used on windows before and not powered down since.

To use the scanner I follow this sequence
1) Boot the machine
2) Power up the scanner
3) modprobe scanner vendor=0x06bd product=0x2091
4) agfafirm  -v /dev/usbscanner snape20.bin
After step 4) the green light on the scanner flashes for a few seconds and the scanner head moves

Log outputs:

tail /var/log/messages
Dec 30 22:48:04 localhost kernel: hub.c: USB new device connect on bus1/2, assigned device number 2
Dec 30 22:48:04 localhost kernel: usb.c: USB device 2 (vend/prod 0x6bd/0x2091) is not claimed by any active driver.
Dec 30 22:48:04 localhost /etc/hotplug/usb.agent: ... no drivers for USB product 6bd/2091/100
Dec 30 22:48:33 localhost kernel: usb.c: registered new driver usbscanner
Dec 30 22:48:33 localhost kernel: scanner.c: probe_scanner: User specified USB scanner -- Vendor:Product - 6bd:2091
Dec 30 22:48:33 localhost kernel: scanner.c: USB Scanner support registered.

cat /etc/sane.d/snapscan.conf
usb AGFA
/dev/usbscanner


 cat /etc/sane.d/dll.conf
snapscan


ls -la /dev/usbscanner
crw-------    1 billy    root     180,  48 Dec 25 22:07 /dev/usbscanner