Hi Andy,
Unfortunately I have not integrated the main site search with the module/skin reviews yet. It is on the pipe though.
But I will show you a hack.
1 - Go to Google.com;
2 - Type in on the search box
site:www.dnnhero.com/module-archive [keyword]
This will find all pages on the module review archive that has the keyword.
Not perfect, but it will do the job.
Cheers,
Aderson