I do it regularly...about every other time I wash my hair...one time curly one time straight....
I use the Avanti blowdryer, it's awesome and a big boar-bristle paddle brush...
I used to use a round boar-bristle brush but I feel like it makes my hair too big...and If I want it completely pin straight I use a paddle brush...
If I'm going out i also flat-iron it with the babyliss 2 inch flatiron...although I don't usually flat iron it...
I use Phytodefrissant from Sephora on it right before I blowdry...
Was 3b then I did a soft relaxer and I think I'm now a 3a
I blow dryed by hair straight for years.... The only way that I was able to my 3b hair to look good was to use the type of blow dryer that has the comb or brush attached to it (not the gun type) and yes, they still make those. I would dry section by section. I didn't use any products, just shampooed until squeaky clean and the conditioned, rinsed then dryed.
When they eventually came out with the professional flat irons, went changed to blowing drying with a gun type dryer till my hair was dry and really wild, then I went section by section with the flat iron and "voila" stick straight hair for days.
Alas, after doing that straightening for most of my life (since I was about 12), except for the Barbara Striesand "natural" that I had and a very few other times in my life I went curly, I'm finally going curly now.
I used to do this almost daily up until a few years ago.
I did it again for a few weekends a couple months ago.
I always use an 1800watt dryer w/ condensor attatchment and a big round brush that's mainly boar bristle with a few nylon bristles that help grab my hair better. I do it a very small section/layer at a time. First I do the section on warm or hot and low, then I do a quick twice over or so on hot and high to set it really straight, then let it cool off and move on.
I've been using a tiny bit of jojoba on wet ends then Giovanni's Frizz Be Gone Balm all over before drying and got great results. (There's a couple pics in my Fotki of the results.) The first time I used a tiny bit more jojoba oil afterward for flyaways but after that I didn't need it (I was jsut a little out of practice but it came back quickly. I did have over a decade of experience to fall back on though. :P)
My hair is almost too long for my trusty ol' standby brush and I can't decide if I should invest in a new one because I don't want it to inspire me to do it more often. :P That one is pretty dang old though so I probably should.
The next time I decide to do it again I'm going to experiment with some TiGi products I got recently. (Superstar Blowdry Lotion and Girl Toys Shine Serum)
I never really got into the whole flat iron thing. My hair looks quite silly without a little curve to the bottom and I could really get it quite straight with just the dryer anyway. Besides, if I flat ironed, my ends would end up flipping out which I hated. Before I learned to blow it out well I would either airdry or rough dry with the dryer then use a large barrel curling iron to smooth and straighten. This was before the fancy-schmancy flat irons were all the rage so I worked with what I had.
If you don't mind -xane cones, I hear that TiGi Afterparty is a good finisher or good to use after drying and before ironing. I can't personally attest to that though because I only use cyclomethicone and dimethicone myself.