idea: auto-generated bookmarks that one's friends might be interested in

the idea is that you should run some browser plugin which tracks your
surfing habits

instead of you manually having to mark everything interesting as
interesting, this plugin would try to figure out what you are
interested in based on patterns

it would also look at the patterns of your friends and try to
cross-match it between you

obviously, it would have to periodically show you a bunch of pages
that it has inferred from your browsing habits, and ask permission to
use them as data. otherwise, you might be embarassed as your friends
learn of your kinky sex habits :)

idea: Quick Sell / Virtual Yard Sale application

Sites like Blocket.se and Ebay.com exist, but I don't know if they are
optimal for sellings lot of small items. Ie what if you want to sell
your entire book collection? You don't want to go through the tedious
process of setting up a sales ad for each item.

Imagine if you could just snap a picture with your cell phone instead.

So, let's say you have 300 books to sell.

1. Yank book out of shelf.

2. Snap photo using Quick Sell app.

3. Here comes the interesting part! How will you input a description
and a price in a quick manner? Some ideas: 1) enter manually using
smartphone 2) enter info later on your PC (ie every items gets added
to a queue) 3) speak info using voice 4) for a small fee, have someone
else enter a description 5) have it auto-scraped from the image (ie
compare with book covers from Amazon) - this is obviously a bit
science fiction but still an interesting thing to ponder. I think all
of these could work, but number 2 seems the best. It can also be
combined with some smart autocompletion look-ups (ie for books or DVDs
and stuff).

4. Goto step 1.

Obviously this would also work for eg cutlery, toys, mittens, and
various other knick-knacks & bric-a-brac. The idea is to create an
online yard sale of all your numerous stuff that you want to get rid
of.

idea: amazon url-shortener that lets you choose whether to use affiliate id

say you want to post a link to a book on hacker news

but you dont want to look like a sleazy douchebag for making money off it

this service would give the guy clicking on your link the choice whether to use your affiliate link or just a blank link (no affiliate id)

this concept can be extended to more sites than amazon.com of course

another side-benefit is that you could log in and change your affiliate id across all your posted links

idea: apps for taxi drivers

what are some cool ideas for apps? might as well harness the fact that they are constantly moving around...

-get your pizza or flowers from a taxi driver
-el cheapo google streetview (mount a webcam in the taxi)
-el cheapo roving security cam
-app for regular customers
-order a taxi driver via twitter
-facebook for taxi drivers
-automated wardriving (ie mapping out networks for everyone's benefit)
-app for tipping
-some kind of bonus app... ie preferred customers can get bonuses and earn extra miles and what not 
-my taxi journey: get statistics on your taxi trips and stuff
-street intel: people on the net can send out questions on the wire to roving taxi drivers and get answers back
-a blog network for taxi drivers

what are some more ideas?