<p>How would you make the contents of Flex RIA applications accessible to Google, so that Google can index the content and shows links to the right items in your Flex RIA. Consider a online shop, created in Flex, where the offered items shall be indexed by Google. Then a link on Google should open the corresponding product in the RIA.</p>

There is a massive thread available here:
http://tech.groups.yahoo.com/group/flexcoders/message/58926
But essentially, google already indexes .SWF files (you can test this out yourself by restricting search results to just .SWF files). It can search any text content within the SWF file.
However, if the text information in your site comes from a database / web server. Then it won't be able to access this information easily.
One example of getting this to work is using an XML file as your index page, then using an XSLT transform to render it using Flex. "Ted On Flex" has good information about this.
http://flex.org/consultants