The IBM T40 Notebook is the ideal mobile computer for those who put a high priority on durability and mobility.  The T40 is very small and very lightweight in comparison to most other notebooks and is backed by IBM's three-year warranty. 

The T40 tips the scales at just 4.9 pounds and measures just 15 x 10 x 1 inch.  That 1 inch thickness makes this unit easy to carry around the office or home.  Tucking it under the arm to carry around is even doable.  When configured so that it is powered by a 1.6 GHz Intel Pentium M processor, 256 MB PC2100 DDR SDRAM memory and a 32 MB ATI Mobility RADEON 7500 graphics chipset, the ThinkPad T40 can efficiently run most standard mobile tasks.  If you want to do the 3-D gaming and high end multimedia tasks then you might want to consider a high-end model Thinkpad, but for the typical users of the world the T40 will do the trick with just about any of your everyday software applications.

Screen

The Thinkpad T40 screen is TFT and includes a 14.1-inch viewing area. The nicest factor in regards to the display is its maximum resolution -- 1,400x1,050 (this is the high-end option, you can also opt for the cheaper 1,024x768).  This offers a very detailed look at your applications.  The display viewing angle is decent, although you might find that the brightness dims a bit as your view moves away from the center -- for some reason the viewing angle doesn't seem as good as even some previous IBM models such as the T21 and T22.  I can't forget to add that this model includes the ThinkLight, an LED that illuminates the keyboard in the dark, this is a great feature.

Keyboard & Navigation

The Thinkpad T40 includes a full-size keyboard and the handy ThinkPad UltraNav pointing device using the oh so familiar red cover that is characteristic of IBM Thinkpad notebooks.  I love the feel of the Thinkpad keyboards.  The keys don't clunk whatsoever, they are quite springy but still give enough feedback to let you know they've actually been hit.  Often times I'll find with notebooks I use that the keys either clunk when hit or you just can't even tell that you've hit the key because the travel (distance the key travels when pushed) on the key is not far enough. 

Ports and Slot Options

The T40 includes the latest high-speed USB 2.0 ports for fast interaction with plug and play peripherals such as external drives and digital cameras, and support for separately available port replicators and docking stations. Connectivity options include a low-speed 56K fax/modem, an RJ-45 Ethernet connector for high-speed Internet, email and network access, and facilities for wireless Wi-Fi equipment.  Unfortunately the T40 lacks an IEEE 1394 port so this makes more challenging to work with digital camcorders or devices such as the Apple iPod.  To round out the expansion slots and ports you'll also get two Type II PC Card slots, headphone and microphone jacks, S-Video out and of course a parallel port on the back edge of the machine.

Processor

The major news is that the T40 is amazingly fast, this is all thanks to Intel's latest generation of thin-laptop processors. Faster but cooler-running than earlier laptop chips, the Pentium M lets vendors squeeze notebooks into smaller cases. As mentioned before the unit I have contains a 1.6-GHz Pentium M chip, this chip contains secondary cache of 1MB, this is a very generous amount and aids the T40 in attaining it's incredible speed. It performs at least 25 percent faster than the Dell Inspiron 8200 machine that I have.  

Battery

With a blazingly fast processor and decently bright screen you might assume the T40 drains the battery pretty fast.  Not necessarily so.  In fact, using a new 9-cell power pack (10.8V, 6,600mAh) the life on the battery ran up to almost 6.4 hours.  The 9-cell pack is more expensive than the regular 6-cell (10.8V, 4,400mAh), but you won't get over 6 hours with the 6-cell and battery life is so key that I can't imagine why you would want to cut your spending dollars on this aspect of the notebook.  If you've got the 9-cell pack then taking the cross country flight from NYC to LA is no problem power wise for the T40.  Want to watch a couple of 2 hour DVD movies on the flight?  No problem.

Sound

The audio in this thin machine seems compromised -- sounds kind of muffled, even though fairly loud. IBM still provides great buttons at the top of the keyboard for controlling the volume.

Wireless

The T40 has the built-in antennas to talk three different wireless protocols: 802.11b and 802.11a Wi-Fi standards along with Bluetooth.  The standard IrDA for exchange of files and communication with nearby laptops is of course included.

Summary

The ThinkPad T40 is expensive, but as usual, you get what you pay for.  The quality of the notebook build and warranty are second-to-none.  Whereas cheaper laptops ship with a one-year parts-and-labor warranty, the T40 comes standard with a three-year warranty. This includes around-the-clock, toll-free phone support throughout the warranty.  The battery performance is fantastic at 6.5 hours and the processor performance although not the best out there is very good.  The screen is great, not as nice as some of the UXGA offerings from Dell, but in general it is adequate for whatever you'd need to use it for in the way of business or productivity applications.  Overall my thumb is up for a buy on the IBM Thinkpad T40,