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:
James Cape 
The prototypes are looking great!
If you mean in the GtkIconView segments (i.e. anything but “custom”), it’ll just keep wrapping until it’s done with the string. If you mean in the GtkFileChooser (“custom”) page, then it will just keep expanding… It’s worth filing a bug against GtkFileChooser, though.
How does your iconchooser work when you have a “veeeery long” filename for a small icon? does it become an unproportionately large grey space all around it that looks bad?
For GtkIconView, would it be possible to cut off very long names (let’s say longer than 2 or 3 lines) by using the new elipsizing functionality from Pango, just to prevent those long and bad (unusable) white spacings between rows of icons?
That’s sort of how Windows does it as well, with the addition that in Windows, you can click on the icon/name to see the whole name without elipses.
Very nice. I posted this to the desktop-devel mailing list on gnome to get a new icon chooser. I hope this gets into the gnome desktop soon.