You'd need to do more things than that, but you're going along the right direction.
PHP is stupid an internally doesn't know what encodings are- so the functions strlen() and some others won't return the length of a string in characters if you're using utf8 - be sure you don't depend upon them.
Also, if you use regular expressions with preg_, be sure to use the "u" utf8 modifier, otherwise you'll get the wrong results (don't use ereg functions ever, they're crap and deprecated).
Additionally, any OTHER systems you're talking to (besides the browser and database) also need to know that you're using utf8. One example is text files - these should be in utf8. A common system to use is email - ensure that your email headers indicate the correct encoding in messages you send.
But the same is true of any third party system you talk to.
Finally, make sure that your .php files themselves are really in utf8, otherwise they will be misinterpreted at runtime. You may need to change your editor's options to do this and/or load and re-save some or all of your files - depending on how many non-ascii characters you use. Web sites in English typically use only a few (but usually more than none)
Mark
