For a long time I have used Skrikers beautifull IImage Browser plugin with Wordpress. But unfortunately: when I upgraded Wordpress to version 2.5.1 the plugin broke. When I click the IImage Browser button, only a popup opens with the site, instead of the usual imageupload/browse popup.
This means I will have to find another plugin that has the same functionality. I have tried the native Wordpress media function, but it isn't near as configurable as the IImage Browser plugin. Too bad...