If you want to add some quick but custom audio to your website and don't want to spend hours (or dollars) doing so, you might want to check out AudioPal, a great free service developed by OddCast - makers of the SitePal Speaking characters we've all come to know and love (or at least used to).
The web service lets you add/create audio by recording a message by phone, a microphone, and even offers a direct audio upload option. AudiopPal also offers a text to speech option (limited to 600 characters) in a variety of languages and voice types.
Users are able to preview the message and then grab a widget/player to include on your site/page. Audiopal provides the option to play the audio recording on page load but I personally advise against that.
I would expect Oddcast/AudioPal to release a pay version of this service in short order.