So, finally got my site back up, thanks to the Debian php4 maintainers for fixing the ABI breakage in the last package revision.
In the meantime I put the iconchooser & friends (md5 hash stuff for GLib, pixbufthumbnail convenience API for GdkPixbuf types, and a thumbnailpreview widget for displaying thumbnails) into libegg. The pattern is similar to GtkFileChooser (abstract interface, w/ implementing widgets). On the TODO for iconchooser is making the theme-switching slicker (it works OK now, but could be cleaner), adding an “icon-size” property, doing a GtkFileChooserEmbed pseudo-proxy impl to fix the tiny default size, and writing the widget, dialog, and button wrappers. Here’s some screenshots: