Actually not that new now
but you can make one yourself now
sorry chinese site
taken from here
Google translated here
P.S. it's not just this that is on the web site they also have details for Lan addators
P.P.S. I'm guessing you could use a spare micro SD adaptor with this instead of a SD adaptor slot as shown
Right now you can rip GD's via SD card and also reupload code to the dreamcast like PD dev emu's ect, not sure what else you can run at this time as I have only realy just got to looking into it myself
check out the posts at benheck forum for the links in there rather than the site itself, this seems to have more info though I have not checked it fully myself....yet