I have put up a new version (v0.3c) of a Perl script that provides Grammar Checking support within LyX's GUI. If you are interested in automatically checking your documents for various errors, see: http://wiki.lyx.org/pmwiki.php/Tools/LyX-GrammarChecker
Internally it checks for a dozen common errors in LyX documents, such as misuse of "A vs An" and forgetting to put a space after a math block. It can be configured to use JLanguageTool to provide full grammar checking from within LyX's Gui, if ChkTeX is installed it will also detect a variety of common TeX related mistakes in your document. Rather than complain each time it is too stupid to understand your grammar, it checks your text against ~400 common errors each of which can be disabled by editing a text file. It seems be quite simple to use under Linux and MacOSX. I haven't tested it under Windows but it should "just work" if you are using Cygwin. I'd be interested to know if it actually does works with Cygwin. If it doesn't "just work", mail me with any errors or symptoms etc. Also if anyone has knowledge of how Cygwin relates to the LyX project, I'd appreciate it if they filled out my stub at: http://wiki.lyx.org/pmwiki.php/Windows/Cygwin?action=edit -- John C. McCabe-Dansted Masters Student