gg25 - 4:09 pm on Jul 13, 2011 (gmt 0)

I think this is "legal":

[code.google.com...]

Question: Does this scheme open the door to cloaking?
Cloaking is serving different content to crawlers than to users in response to a given URL. This is generally done with the intent of boosting one's ranking in search results. Cloaking has always been (and will always be) an important issue for search engines, and it's important to note that making AJAX applications crawlable is by no means an invitation to make cloaking easier. For this reason, the HTML snapshot must contain the same content as the end user would see in a browser. If this is not the case, it may be considered cloaking. See our article on cloaking for more details.
Can I use this scheme to help with making my Flash or other rich media files more crawlable?
Although Google does index several types of rich media files, and although we are continuously working on improving our crawling and indexing capabilities, there are circumstances under which it may be appropriate to provide the crawler with content that is otherwise not visible to it. For example, the crawler may not see all the content of your Flash application. As this is a parallel situation to dynamic Ajax content not being visible to the crawler, you are free to use the scheme described here to provide the crawler with the additional content. However, you have to make sure that your site will not be suspected of cloaking. Again, the HTML snapshot must contain the same content as the end user would see in a browser, and Google reserves the right to exclude sites from its index that are considered cloaking.