I used to go 2-3 days without washing my hair (pre-primal, typical college eating) before it would get unbearably greasy. It helped that I had short hair that looked best as though I'd just rolled out of bed (showering at night helped). It did take a couple of weeks before my head really adjusted. Now I have longer hair, so the transition period is not something I'm looking forward to. It's also very thin naturally, so grease really shows up no matter how I style it. I desperately need a trim (split ends are increasing aaahhh!), but intend on trying to go without washing for longer once that's under control. My hair has been so dry lately that I can often get away with just conditioner and it looks/feels fine.
I'm very interested in Lush's natural products (see LUSH Fresh Handmade Soaps and Natural Cosmetics). I used their henna (caca rouge & brun mixed) a couple of times and it made my hair feel great, though it smells quite odd. I think I'll do it again soon for a more natural change (used to have pink hair, I still miss it). I can still see a slight color change several months after the last application, which means I probably can't bleach/dye my hair with anything else until it grows out =\
I recently started using baking soda as deodorant due to uncomfortable underarm itch and my usual deodorant choices no longer working. No more itching and no more smells! My underarms are also much smoother when I wash them, which is nice. I plan on emptying a baby powder container and putting some baking soda in there so I can bring it to the gym/travelling. It also doesn't leave marks on my shirts as long as I brush off the excess with dry hands.
Current interests - Starting Strength (reading it very slowly)