How can I add more filetypes, but for download only?

[jeremed]

I need to add some extra filetypes like ai, eps, psd etc... but for download only. I would like to be able to have a representative AI thumbnail for example that would link directly to the download file. Any help or suggestions would be awesome.

[Nibbler]

Add the extensions into the cpg_filetypes table as documents and use extension level custom thumbnails.