however finding the right build can be slightly daunting.
head on over to http://www.desipro.de/ddwrt/ in a new tab so you can follow along.
not many devices are supported with Kernel 3.0, so you want the K26 directory
at this point there is a bunch of build numbers. you want the highest build number, which will have the most recent date. as of this posting, that is R22200, built on 18-Aug-2013 10:18.
so now there is several crypticly named builds there.
kingkong builds are only good on routers with 16+mb of flash. which you probably don't have.
The Belkin Share and Sharemax both have 8MB flash, so its down the the ones starting with usb-ftp-samba3.
so look at the filenames there (you may have to mouseover to see them)
the nv60 and nv64 builds require 60 and 64kb of nvram. which you probably also don't have.
the Belkin share and sharemax have 32K of nvram. so you want one of the nv32 builds.