Google offers some cool gadgets that will work on our Ning Networks. I have attached a text file that contains the code for a crawling spider. This code will fit in the center column. All you have to do is: add the code to a text box.
Also, here's the Google page link, where you select other gadgets. Not all will work within a Ning Network. But, you can customize the area size where your spider will crawl.
Google Gadgets
This one gives me the 'willies', but wow is it effective! All for fun, a crawling spider! See attached file for code.

Be careful, the gadgets are created by Google users, not Google. Personally, I would not use the gadgets that have Google Ads embedded. The gadget creator is making $$$ off your site visitor's clicks. If you do not pay premium service from Ning, you could be violating their TOS.