From Internet Tablet Talk
Host Mode for OS 2008
(Tested on an n810)
Basics
Given the necessary micro-mini-normal-USB adapters and gender-changer-adapters you can connect external harddiscs etc. to your Nokia N810 and it will mount them automatically. But only if these devices are either "self powered" (harddisc video players like Archos and such) or are connected via a powered USB-hub. The devices can be unmounted via the symbol next to WLAN and stuff, in the info area top right.
Advanced
If the devices don't automount, read:
HOWTO USB host mode
and then these advanced infos:
This will enumerate hubs (though it will give an "unsupported" notification), which helps especially with power. Except for flash drives (including internal versions such as cameras or MP3 players), keyboards and mice, most things will need external power.
It will mount nearly any USB drive including half-terabyte MyBooks, (FAT) iPods, and flash drives. Some multi-readers won't have all sub-devices (LUNs?) mounted automatically, e.g. my Belkin sees the XD and CF cards, but not the SD. (Is there a way of umounting without the terminal?). Except for the flash thumb-drives, I needed a powered hub, and a HFS+ iPod was recognized, but the mac partition scheme wasn't.
If you compile kernel modules, it will recognize other file systems including hfs+, but not the Mac partitioning scheme (does this need a new kernel?), so a Mac iPod won't work. The hfsplus.ko wouldn't work with "mount -t hfsplus /dev/sda /media/ipod -o loop,offset=xxxx" which would work on my laptop saying the hfsplus couldn't parse the options.
With sr_mod.ko and cdrom.ko it will recognize CD/DVD drives, but you will need isofs.ko and/or udf.ko to read them. It won't automatically mount them so you need to open a terminal and do "mkdir /media/cdrom; mount /dev/sr0 /media/cdrom"
With cdc_acm.ko, one USB to serial adapter worked (which appears as /dev/ttyACM0 - most use usbserial.ko, and for cell-wireless, airprime.ko).
Linksys USB100M is recognized and works (apparently doesn't need any new kernel modules, and doesn't need external power or a hub), but I don't know how to make it automatically do "udhcpc eth0", which I do from an xterm (or you can set the IP directly, or host DHCP). But if you need true ethernet instead of wireless, this works.
