date & time conversion confusion

hey folks - i'm having trouble figuring out how to convert an existing date & time into a more friendly format in PHP. I've used MySQL's date format which stores the values as YYYY-MM-DD. Now when I select these values from the database and display them on a web page I'd like to format them along the lines of MM-DD or Jan 01 or January 1 etc. I've looked into PHP's built-in functions time() mktime() getdate() etc, but none seem to work with existing values. Can anyone shed some light as to how I would go about doing this? I know in Perl there are tons of external libraries to do such things... are they available for PHP? Another issue is how I go about converting 24 hour time (00:00:00) into more friendly "XXam". Any help would be greatly appreciated. Many thanks, Brian