Can anyone advise techniques that can be used with echo2 applications for search engine optimisation (SEO)?
A good start would be to be able to set the <title> and <meta> tags in the BaseHtmlDocument before its written to the browser. The only way I've found to do this is by overwritting the WindowHtmlService.
I suppose another approach is to have a web 1.0 site and limit echo2/ajax use to those areas of the site that do not need to be indexed by search engines.