URL shorteners suck
kottke.org
kottke.org
where XXX.YY is some suitable 6 letter domain name and ABC is a three letter hash. Assuming three letters from the valid [0-9A-Za-z] you have 62^3 possible links _per domain_. Extending to four characters you'd have 62^4 (over 14m links _per domain_).
So an amazon.com link would drop to 25 characters. A TinyURL link is currently 25 characters (bit.ly would be 18). So this is still in the ballpark.
Of course, the results aren't consistent (e.g. a ycombinator.com link would have 30 characters). But it would give a lot of information. Also, I think for non-.coms you'd have to include the TLD.
An advantage of using subdomains it that on YC/Reddit/Digg these links could easily be made to show as, for example, amazon.XXX.YY
It may be worth also allowing users to suggest the shortening of the url the first time a domain is submitted. Just truncate ycominbator to yc etc.
I love this idea and if you decide not to pursue it, please let me know as this is something I would eagerly work on.
I reckon I could get this up and running in about an hour if enough people upvote this comment :-)
And, also, I agree.. URL shorteners suck. At least improve user experience by showing the original URL in the title attribute.
You probably meant it that way but many people seem to forget over the hype how small twitter still is. Only 0.4% of internet-users have an account there and much less are actively using it.
Consequently short URLs being ubiquitous within twitter doesn't mean much in itself.