Absolutely; and I keep mine still for doodles that become patent ideas (signed and dated), for taking cornell notes of meetings and phone calls, and that kind of thing. I prefer these though: http://www.leuchtturm1917.com/en/content/medium-notebook (and the dotted paper is more useful than the squared). Tried moleskins, tried Paper Blanks, tried a few others, but the 1917s are the best I've found...

...but they've become my first draft, rather than my only notebook. It's just too easy to grab a chunk of an email or a graph's png or a code snippet and lob it into the vimwiki; and it's where I work up most of the stuff that goes into papers or patents.

I'm a big fan of Doane Paper. Lines AND Squares. http://doanepaper.com/

I know some people who used an electronic system which printed out a barcode encoding a cryptographic hash of each entry, which could then be stuck in a paper notebook with numbered pages, and dated and witnessed.

This combined a legally admissible chronological record in physical form, with all the benefits of electronic records.