Do I need to use condoms if my boyfriend might have an STI and not know it?

If my partner and I have been monogamous for three years (and I was a virgin before we met) and my partner tested negative for the HIV virus (twice, about two years ago, with a six-month gap between the tests) is it safe for us to use a birth control method other than a condom? That is, are there still any STDs that my partner might have without knowing it, that we should be worried about, even though nothing whatsoever has seemed wrong with either of us for three years and my partner has had several regular annual physicals in that time?


How can I start practicing meditation, yoga, or tai-chi?

Recently I've been thinking a lot about ways to relieve my stress and other mental problems such as OCD and ADD and I have been hearing that meditation, yoga, tai-chi, etc. can possilby help with these problems that I have been suffering with all my life, but I am very confused as to which one would be the best for me.

Also, if I find out which one would work the best for me, how would I go about finding someone that could teach me these things? Or is a book a good way to go? If a book is a good way to go would you suggest one of those "The Complete Idiot's Guide to..." books?


Is my hair addicted to dandruff shampoos?

I have dandruff that responds well to over-the-counter shampoo. Ergo, I have been using the stuff almost exclusively for ten years. No brand in particular, sometimes zinc pyrithione (the blue stuff!), sometimes coal tar (the smelly brown stuff!). Anytime I switch to non-dandruff shampoo for like three to four days straight, I get my dandruff back. I worry that I might be addicted to dandruff shampoo. Should I worry?