There aren't too many situations where a 302 is appropriate. How often have you temporarily moved a page? It's much more common to move pages permanently. Nevertheless, it seems easier to create 302 redirects than 301s. You can use Javascript or a meta tag to create a 302. Creating a 301 redirect requires special commands in your .htaccess file if you use an Apache server. With Windows servers, creating 301 takes even more time and trouble. That's why there's a tendency for people to mistakenly use 302 instead of 301.