Gmail? Sorry, every variant of your name is taken. Twitter? Every witticism, every pop culture reference, every real name, all taken. Just add another number to the end, I guess. It must get you down when you feel like you're always part of the 3rd/4th/5th wave of everything.
How many people here have tried to get a Twitter account for their new company, only to find an existing account that tweeted some spam once eight years ago and has been dead ever since? For services that have global reach, the problem gets bad real quick.
We really should think hard about whether we can namespace the population in some way.
Contrary to the thrust of this article from Jon, I'd also like to see more aggressive cleanup for some services. If you have an S3 bucket and it has no activity for 15 years, you're just squatting and I think you should arguably be warned, and then finally have the name recycled. Same goes for Twitter accounts that have never posted, retweeted, liked a tweet, etc and not been logged into for over 10 years.