From Wikipedia, the free encyclopedia:
ThinkPad is a line of laptop computers and tablets by Lenovo. The series was originally designed, developed, and sold by IBM until Lenovo acquired the brand in 2005 after purchasing IBM's personal computer business.

ThinkPads are known for their minimalist, black design which was initially modeled in 1990 by industrial designer Richard Sapper based on the concept of a traditional Japanese Bento lunchbox revealing its nature only after being opened.[1][2][3][4][5][6][7][8][9] According to later interviews with Sapper, he also characterized the simple ThinkPad form to be as elementary as a simple, black cigar box and with similar proportions that offers a 'surprise' when opened.[10][11]

ThinkPads are popular with large businesses and schools Older model ThinkPads are revered by technology enthusiasts, collectors and power users due to their durable design, relatively high resale value, and abundance of aftermarket replacement parts. ThinkPad laptops have been used in space, and was by 2003 the only laptop certified for use on the International Space Station.[12]
The name "ThinkPad" is a product of IBM's corporate history and culture. Thomas J. Watson, Sr, had first introduced "THINK" as an IBM slogan in the 1920s.[15] As stated above, the name was initially opposed by the IBM corporate naming committee as the names for IBM computers were all numerical at that time. With time, "ThinkPad" stuck due to praise from journalists and the public.
Traditionally black, ThinkPads have commonly featured magnesium, carbon fiber reinforced plastic or titanium composite cases. The ThinkPad has introduced innovations, including the TrackPoint pointing device, the ThinkLight, a LED keyboard light at the top of the LCD screen, the Active Protection System, an accelerometer sensor which detects when a ThinkPad is falling and shuts down the hard disk drive to prevent damage, roll cage design to minimize motherboard flex, stainless steel hinges, a biometric fingerprint reader, Client Security Solution, which improves security using a built-in Trusted Platform Module (TPM) and facilitates deployment in corporate environment, the ThinkVantage Technologies suite of computer management applications, and drain holes to help reduce damage to the keyboard and components from accidental spillage.
Since 1992, the ThinkPad design has been regularly updated, developed and refined over the years by Sapper[11][18][20][26][27] and the respective teams at IBM and later Lenovo, which included Yamazaki, Tom Takahashi, Sam Lucente and, since 1995, David Hill, Vice President of User Experience & Design, who leads and manages the design/user experience of ThinkPad.[4][5][11][24] Hill's approach to maintaining the evolution of Sapper's original ThinkPad design is analogous to how Porsche manages evolution of the classic 911.
In 2012, Lenovo partially moved production of its ThinkPad line of computers to Japan. ThinkPads will be produced by NEC in Yonezawa, Yamagata.[50]
The T Series historically had high-end features, such as magnesium alloy rollcages, 7-row keyboards, screen latches, the Lenovo UltraBay, and ThinkLight. Models included both 14.1" and 15.4" screens available in 4:3 and 16:10 aspect ratios, with premium durability, usability, comfort, and design taking priority over minimalism.

Typical T400 for sale on Ebay:

A Typical Amazon user review:
5.0 out of 5 stars Better than a MacBook Pro, March 10, 2012
By O. Medeiros -
This review is from: Lenovo ThinkPad T400 7417 (Personal Computers)
If you want a performance laptop with durability and reliability, look no more. ThinkPads have been the top of the line laptops for IBM and now Lenovo. I bought this for half the price of what a MacBook Pro costs and performed some easy installation upgrades such as Solid State drive and 8GB of Ram. With a Macbook you have to do a bit more work just to perform these tedious upgrades (Apple doesn't like it when you open up their products).

This Laptop is lightning fast, the keyboard is a joy to type on, speakers are great, webcam view is clear and the very cool thing about this laptop is the Ultra bay hot swap. If you don't use the CD/DVD recordable drive as much, you can easily eject it by pressing the Ultra bay eject tab and insert an additional battery or an extra hard drive for backups. This feature is very very cool and you can't do that on a MacBook Pro!

Windows 7 Ultimate 64bit runs flawlessly (thanks to Microsoft)and by far is the best Windows version Microsoft has ever built. The BitLocker encryption is a plus which allows you to encrypt USB, SD cards, folders, files or the hard drive itself for extra protection. But if you want security, this laptop has another cool has an accurate fingerprint reader that allows you to associate any finger with your password(s). In other words, no more typing passwords to log into Windows. When you boot up your laptop, it prompts you to swipe your finger and presto! Without the finger swipe, no thief or intruder can wipe or access or remove your hard drive without that finger print. You can't do that on a Macbook Pro!!

Finally, I love the so called rollcage technology (durable frame inside)that guards it from those accidental drops. It also has a cool drain technology for those accidental can't do that on Macbook Pro!

So do yourself a favor, if want want more bang for your buck with all these extra goodies and performance, get a ThinkPad!

Thinkpad info
Thinkpad T400