(Image courtesy of Apple) (Image courtesy of Apple)

Earlier this year Apple announced plans for a redesigned Mac Pro that's significantly smaller than its predecessor and has a very different shape. If rumors are to be believed, more details about the product should be unveiled Tuesday.

If Apple did decide to give its latest desktop Mac an unconventional shape, it shouldn't be a surprise. For more than a decade, the Cupertino, Calif., firm has relished introducing products that look radically different than what came before. These products make creative use of shapes such as cones and cubes, are aggressively minimalist and in many cases are dramatically smaller than anything else on the market. Here are five examples of Apple's penchant for thinking beyond the box.

(Photo by George Kelly)

1. The Airport Base Station

Apple was one of the first companies to adopt 802.11 wireless networking, a technology it rebranded as "Airport." In addition to adding airport card slots to all of its desktop and laptop computers, Apple introduced its own WiFi base station in 1999.

A normal company would have designed the Airport base station as a flat, rectangular box. But Apple's designers thought differently, creating a product that looked more like a flying saucer than a piece of networking gear.

Alas, the UFO look didn't last. After several iterations, Apple finally replaced the original design with a more conventional rectangular shape.

(Photo by Carl Berkeley)

2. The "sunflower" iMac

The design of the original iMac, introduced in 1998, was hardly boring. It had a curvy shape, came in unusual colors and sported a translucent plastic that let users glimpse the machine's guts.

But Apple outdid itself four years later when it introduced its first major overhaul of the iMac line. The new iMac was beautiful, but it looked suspiciously like Luxo Jr., the famous animated desk lamp created by co-founder Steve Jobs's other company, Pixar. The compact base housed the guts of the computer, while the highly adjustable arm allowed users to move the iMac's screen exactly where they wanted it.

In 2004, Apple overhauled the iMac again, introducing the modern iMac form factor, with the guts of the computer tucked behind a sleek flat-panel display. It's an elegant and practical design, but it's not nearly as much fun to look at.

(Photo by Patrick Kuhl)

3. The Power Mac G4 Cube

Jobs, who died of cancer in 2011, had long had a passion for cubes. The flagship computer of the company he founded after he was ousted from Apple, NeXT, was a black cube. NeXT's hardware line didn't get traction, but after Jobs returned to Apple he gave the cube shape another try in 2000.

The design was widely panned. Introduced at $1,799, it was too expensive for casual customers, and its small size made it unsuitable for power users who wanted expansion slots. People mocked the design as a "Kleenex box." It was discontinued after one year.

A few years later, Apple introduced the Mac Mini, which had a footprint almost identical to the G4 Cube but was much shorter. With prices starting at $599, it proved much more popular than its taller forefather.

(Photo by Michael Karshis)

4. The "hockey puck" mouse

Few products have been more widely mocked than the mouse that came with the original iMac in 1998.

Critics derided the mouse as a "hockey puck." Some said that its diminutive size made it impractical for people with larger hands. Others complained that its perfectly round shape made it hard to hold the mouse right-side up.

Still, Apple stood by the new design for two years, shipping the mouse with all of its computers. Finally, in 2000, it discontinued the device in favor of a more conventional oval-shaped pointer.

(Photo by Wesley Fryer)

5. The no-button iPod Shuffle

Apple's iPods always pushed the envelope on tiny, minimalist designs. The original iPod sported a clean, simple interface, and the iPod Mini and iPod Nano were even smaller and simpler. But Apple's obsession with miniature music devices reached its pinnacle (or, depending on your perspective, it nadir) with the third-generation iPod Shuffle.

The first two generations of the Shuffle had buttons but no screen. The third-generation Shuffle dispensed with buttons altogether. Users who wanted to control what music was played could plug in special Apple headphones with controls on the cord. Otherwise, the device would automatically start playing the user's default playlist when switched on.

This design lasted only a little more than a year before Apple came to its senses and reintroduced buttons for the fourth-generation Shuffle.