I've looked around for a flash cart that would be flush with my DS as well, and I contacted the owner of www.jandaman.com for details. He said that he would be stocking the ez4lite (a cart that uses micro-sd cards, or T-flash cards) in a couple of weeks when it comes out.

19:26:41) jandaman1979: i will be getting the ez4lite in a couple weeks that's flush with the ds

He also said that it would cost around 60 dollars.

Nobody knows yet how good the interface is yet, but Hoowahman's post:

I think you should wait for this to come out.. it is flush with the nds lite:

http://forums.maxconsole.net/showthr...531#post176531

gives some pictures of what it looks like. Personally, I'd wait for the G6 lite, because even though the storage is non-swappable, it is made by the M3 team, who historically have a good interface and compatibility w/emulators. (Look at the M3 Perfect)