Been getting quite a few requests for libgio bindings. I whipped up a new module in mono svn to provide an unstable binding for people who want to experiment and help refine the API. It is my intention to eventually, most likely in gtk-sharp 2.14, merge this binding into gtk-sharp and eliminate the standalone package. Until then, it will install per the Mono Guidelines for Unstable Library Deployment outside the GAC.
For the extremely impatient and adventurous, you can find it at trunk/gio-sharp. You will need GAPI from trunk/gtk-sharp to build it. It still throws tons of generation warnings. I have made zero attempts to use it. It has no docs. If it melts your laptop, don't complain to me.
Feel free to file bug reports for anything out of order. I'll try to be responsive to any reports, and as always, patches are welcome.