Given all the "DS controls suck"-talk, this might be of interest:
http://www.amazon.de/Nintendo-DS-lite-P ... 355&sr=1-1
It´s basically an additional battery, but the snap-on handles are what made me buy this. There are similar products for the PSP, and I had one for my GBA SP (the snap-on handles, not the battery), which was BRILLIANT. Given that the d-pad on the DSL is already a bit problematic, this one here might at least remedy hand cramps and improve the button control quite a bit. I don´t really think I´ll use the battery in it much as I mostly play DS at home, but who knows, might be good for the occasional train ride
I´d still rather have just the handles, but simply couldn´t find anything similar, which is a bit sad, given how much "value packs", "modding skins" and other useless crap is avaiable for the DS.
It´s a bit expensive, and I couldn´t find the product on non-german Amazon sites, though I´ve read that the same product is made by Nyko, too (it´s supposed to be discontinued, though). I´ve read that these handles are very comfortable in several forums, so that was a no-brainer for me.
EDIT: Here´s the official product page:
http://www.logic3.com/details/?prod=168