July 26, 2005: Apple debuts the opaque white iBook G4, the last of its laptops to launch under the iBook name.

The portable computer adds Apple’s scrolling trackpad for the first time. It also incorporates Bluetooth 2.0 as a standard feature, and becomes the last Apple laptop with a PowerPC chip.

iBook G4: A rugged laptop

Compared to today’s ultra-thin MacBook Pros, or even 2008’s MacBook Air, the 2005-era iBook looks quite chunky. To put it into perspective, the now-discontinued 12-inch MacBook was thinner than just the lid of the iBook G4.

However, what it lacked in skinniness, this rugged laptop made up for with plenty of power under the hood. Compared to the late-2004 model, it boasted a faster processor, twice the RAM (512MB versus 256MB), an extra 10GB of hard drive space and superior graphics.

In addition to the new trackpad — which let users scroll using two fingers — the final iBook also included Apple’s clever Sudden Motion Sensor technology. Designed to stop the hard drive heads from moving if the laptop sensed it had been dropped, it protected against data loss.

Both of these features previously debuted on Apple’s high-end PowerBook G4 computers. Their arrival on the iBook made them available to average users. A scan of the original iBook G4 instruction manual (.pdf) shows all the features.

iBook is an important step toward MacBook

Starting with the very first iBook in 1999, the line of popular laptops marked an important era in Apple history. From the colorful iMac-lite original to the plasticized iPod-style white versions later on, the iBooks helped make Apple laptops cool and ubiquitous during their seven years on the market.

Apple discontinued this particular iBook model on May 16, 2006. The company then switched to Intel processors and rolled out its MacBook product line.

Did you own an iBook? If so, which model was your favorite? Leave your comments and reminiscences below.