It does play a role although I do not know how much.

Just search "PDA accessories" on Google and you will see


Derek

[DELETED]

you want:
short as possible
easy to remember
keyword friendly
and if the choice comes up...
.com before .net before .org before anything else

I've seen several techniques that use the product name as the domain, like panasonic dvd x2000, or sony viao laptop, several other threads have said the same thing. You can also add words like 'review' at the end or 'buy' at the beginning

careful w/ the trademarked names in domains, you may receive a cease and desist and then all the effort link building is for naught.