I blogged about this earlier, but here are some new thoughts about how it should work.
I would like my Weblog provider to auto-cache every URL I link to from my blog. When I put a URL into the content of a posting, my Weblog engine should strip it out and replace it with an intermediary URL. The intermediary URL should go to a page that provides the actual URL that I put in my content, as well as another URL that links to a cached copy of the content that I linked to originally.
The cache-link could point to Google’s cached version, or better yet to a local cached hosted by my Weblog provider (Google does not guarantee that cached copies will always be available, whereas my Weblog provider could make that guarantee; furthermore Google may not even have a cached copy of the item I link to, whereas my local Weblog provider could make that cached copy at the time I post the article).
This would ensure that all content that I refer to in my Weblog will always be available, even if the original source is taken offline. I think this is essential — without it someday a significant portion of the links in my weblog may be broken due to content going offline or moving, which would render much of my Weblog content obsolete.
There are some copyright issues to consider perhaps — but I am not sure they are obstacles. After all HTML does provide a way to designate that a page should not be cached, and Google is caching a lot of pages without any legal challenges. Another approach to this would be to use the Internet Archive as a cache — at least they are non-profit, thus perhaps the legal issue of hosting cached copies of sites may be easier to resolve: they do it already.
Perhaps my friend Brewster and his pals at the Internet Archive should create an API that bloggers can use for this purpose. When the API is pinged with a URL, the archive makes a cache of that URL and returns a new permalink to that cached copy. Blog engines can use this API to submit URLs and get cache-URLs in return, which can then be inserted into blog postings automatically for the posters. This would be a great use of the Archive and would help bloggers immensely.