i've had urlpick.com since 2002 and i hand-coded a one pager in notepad for domainsupermart.com
design on both ain't the best, but urlpick makes $$$ a year in adsense, which pays over the cost for renewal and hosting.
rarely updated, but still get referrals and inquiries, has some pr, links and is google/dmoz listed.
though as Raider alluded to, it may be better to just park your names, as maintenance of these sites takes time, and time is money.
you'll have to decide whether to have traffic from all/most names directed to your sales site or park/develop some and just use the site as a listing.
imo...
wanted to add in here, that i also use urlpick to host my mini-sites.
examples:
urlpick.com/recyclableplastics.html < recyclableplastics.com
urlpick.com/reusableconstructionmaterials.html < reusableconstructionmaterials.com ** 1st page in Google
urlpick.com/wheat.html < wheat.biz
above i redirect the .com/.biz to their respective pages.