In order for a gadget to be listed in Gadzi, it must first be submitted to two places Google Gadget Directory and Google Modules which are mentioned above.
Once your gadget has been submitted to the above resources, this sites' editors will have the ability to use, install, and review your gadget.
The Gadzi directory is only accepting submissions for the specific subjects listed which are listed on their home page at the moment. To submit your gadget to us, please be sure you have submitted it to the above directories, and then send the URL of your gadget to firstname.lastname@example.org. Please note that Gadzi is very selective in what they accept into their directory.
I found this website recently. Earlier there used to be website named Google Mini Apps. Looks like that website got renamed to AppFoyer as their interface is same.
Submitting the gadget here is quite easy. Just give the url of your Gadget which you want to submit. Select the Categories in which you want to place your gadget. Accept their terms and conditions and your gadget is submitted. Do checkout their website now.