Since writing my entry about the problems of URL shorteners, where I linked to two articles I read on the subject, I found some other opinions, suggestions and potential solutions on the subject.

The most obvious risk associated with URL shortening is that it's difficult to know where the URL will take you, until you click it. … With a shortened URL, it's hard to know where it will take me, until I click it. Email Phishing scams are using URL shortening service for this very reason.

The Security Implications of URL Shortening Services by David Weiss.

It's a mistake, in hindsight, for Twitter to give us TinyUrl URLs, because the link depends on two companies and two servers. It would be better if it just depended on one, less likely to break.

Solving the TinyUrl centralization problem by Dave Winer.

Both Kellan Elliott-McCrea and Jeremy Keith are suggesting a solution using the existing HTML attributes of rel and rev with a new property that works in-conjunction with the recently introduced rel="canonical" system Google announced. Kellan Elliott-McCrea has created RevCanonical a "URL shortening that doesn't hurt the Internet" which implements the new this property behaviour. Robert Spychala has a proposal called Short URL Auto-Discovery.

If you're linking from the canonical URL to an alternate URL (like, say, a shortened URL), you could use rev="canonical": the relationship of the current document to the linked document is “canonical”.

Adactio: Journal—Shrtr by Jeremy Keith.

A consensus I have found from multiple channels seems to be that the service requiring the 'need' for URL shorteners – such as Twitter – should provide a short URL system itself. Therefore, if (or when) the main service becomes defunct or closes down, the shortened URL is lost with the main system that required it. This helps, but does not completely irradiate, the problem of "link rot" which would happen if just the URL shortening system died.

In cases where shortening is necessary, Twitter should automatically use a shortener of their own. That way, users know what they're getting and as long as Twitter is around, those links stay alive.

URL shorteners suck by Jason Kottke.

Finally, I noticed Jeffrey Zeldman post an interesting link on Twitter which pointed to his domain, followed by /x/7, which redirects to another website. I imagine this is similar to a brief idea I had — use your own domain as a shortening service. Now, this won't work in a lot of cases, especially if you have a long domain, but it adds two factors to the equation. Firstly, trust — I am instinctively more trustworthy of the link as it is a personal website and not some generic service anyone is free to (ab)use. Secondly, this could act as a personal "favourite, useful or interesting" link archive. You may not be interested in keeping every single link you shorten, but you are shortening them for a reason, and with a personal archive that reason is kept and not simply forgotten. A caveat is that this does not solve the problem of "link rot" as you are likely to distribute the shortened link on services such as Twitter. An interesting thought, though, and something I may implement myself.