The 909 D2 is the newest Titleist range, but there will be a new one very soon. The 905r is the traditional pear shaped driver but is about 5 years old. They are both good drivers but you could pick up a 905r very cheaply.
2008
Titleist 909 D2, 8.5O with Fujikura Rombax 7V05.
I believe the most popular driver is the Titleist 905r Driver. Their new model the Titlesit 907D2 will probably take the mantle in the future
A Titleist Driver can be purchased at many golf stores. Here are some of those stores 3 balls, Golf Galaxy, global Golf, PGA Tour Shop, Golf Locker, Amazon, Ebay, 2nd Swing, and Fairway Golf USA.
Tiger Woods uses these clubs: his driver is the Titleist 975D, his 3 wood is the Titleist PT 15, his irons (2-PW) are the Titleist Tour Forgings (681), his wedges are the Vokey 258-08 and Vokey 260-06, and his putter is a one-of-a-kind Scotty Cameron by Titleist . He uses Golf Pride Tour Velvet Cord grips.
Titleist was created in 1932.
Ian Poulter normally uses a Cobra ZL Driver, a Titleist 909 F2 Fairway, Titleist Vokey Wedge, Titleist 909 H Hybrid Fairway, Cobra Pro CB Irons, and a Rife Aruba Putter. But at the Royal Birkdale, he used: Driver: Cobra Speed Pro Fairway Woods: Cobra Speed Pro Irons: Cobra Pro MB Wedges: Vokey Design Spin Milled Putter: Odyssey Black Series This is according to data from when this questions was asked (July 13, 2010).
Absolutely zero. He is not sponsored by Titleist. He only uses a Scotty Cameron putter which is under the Titleist brand, but he does so out of choice.
Titleist dead center model SP-201UP
This is because Titleist has agreements in place with PGATOUR.COM and The Golf channel that they will indicate which players use a Titleist ball.
The Titleist Pro V 1 is a 3 piece ball. The Titleist Pro V 1x is a 4 piece ball.
DL3 plays the Titleist D910D3 Prototype with adjustable hossel. He played for years the D909 and was one of the last pros to switch from a persimmon driver to a metal driver (1996). He is still in the top 15 long hitters on tour at 46.