Has anybody here written, or encountered any analytical essays on TP, not so much about the content, but form, eg this splendid wee read:   http://www.geocities.com/~mikehartmann/papers/detective.html

I'm just interested is all

there's a book called Full of Secrets: Critical Approaches to Twin Peaks. i haven't read it but it looks like it might be what you're looking for. it appears to still be in print, you can get it off Amazon.com.

Like Empress151 says Full of Secrets is an excellent start - there's a a section at the end of the book that's a conversation between the essay writers on Twin Peaks and post-modernism which is probably one of my favourite pieces of writing on the series as it really starts you thinking. There was an issue of Film/Literature Review which I've seen floating around in pdf (I'm sure someone on the boards would have it for you) which had a large section of excellent essays on TP too. It's well worth trying to hunt down as it's an excellent read.