I like that WordPress has a built in permalink builder, however I wish it had a built in way of adding your own custom rules. You can, however, write a function to hook with the flush_rewrite_rules() built in WordPress. I borrowed some of Sergey Chernyshev's .htaccess lines and created a function to add gzip compression and caching rules to speed up WordPress load time.
Achievements seem to be popping up in every new web service. Why? Because achievements make you win the Internet. Okay, not really, but it does make your user feel more engaged into your web site. It gives the user a reason to use your site and do more things on your site. The best part is the achievements do not even need to be all that difficult.