Nice stylish t-shirts with the maemo.org logo on (perhaps less large than last year == more discrete == more likely to be worn in public ;-)).

Perhaps see if we can get them in a grey close the header above, with the white & orange logo on the breast? I don't think there's a need for a big design competition for them: there's enough to do without organising one.

Stickers: fine, but my son's laptop is the only one which get adorned.

Perhaps a USB adapter/cable for OTG host? Or if not, a shop selling them on site, along with other cool hard hacks.

I think a t-shirt's the only essential item, but things somehow related to Maemo rather than the standard conference stuff would be good. I was at a rather larger conference last week and they gave out anti-bacterial alcohol hand gel (norovirus outbreak the year before). Do not recommend ;-)