Well authored urls make for good SEO. One the simplest ways to do this is to write good titles to your entries and then MT will dirify the title to create a basename from which the url to the entry is created. But if your entry title is longer than 100 characters, the rest of the url is clipped.
Good news! Basename can be increased to 250 characters. As it seems that most people would prefer unclipped urls to long urls, I added a feature request to increase the default to the max of 250 characters. Then if a user prefers to have smaller urls, they can modify this setting.
To change your default, navigate to Preferences > Entry Settings, and change Basename Length to your desired length.
My thoughts on the subject:
http://jayallen.org/2008/09/oh-awesome-I-cant-wait-for-the-proliferation-of-idiotically-and-needlessly-long-urls-that-look-like-ones-created-by-spammers-because-as-we-know-users-dont-read-or-change-defaults-they-only-complain-yes-that-will-be-great-for-the-web-and-for-all-of-us.html
Fair ‘nuff… some MT users could be considered spammers though ;)
Spawning another idea… when you create a blog, perhaps you have the option to do an “advanced setup” where you can set many more options… one of these options could be offer the ability to choose from among a common set of archive path configurations for all published fields.