Apple’s market cap edged over Google’s to hit $159 billion today (kudos to AllThingsDigital’s John Paczkowski for spotting this).

Is the maker of the iPhone, iPod and Mac worth more than the top Internet company’s $157 billion? How soon might either beat tech stalwart IBM, which is now worth $170 billion?

Mull over these stats to help you decide, courtesy of Reuters Estimates:

Forecast fiscal 2008 revenue
IBM: $109 billion, Google: $22 billion, Apple: $33 billion

Forecast FY2008 profit (excluding special items)
IBM: $12.2 billion, Google: $6.3 billion, Apple: $4.7 billion

Share price rise/fall in the year to date
IBM: +16 percent, Google: -28 percent, Apple: -9 percent

Forward price/earnings multiple
IBM: 14 times, Google: 25 times, Apple: 34 times

In case you’re wondering when any of them might catch up with the world’s largest tech company, they’ve got a ways to go yet. While Microsoft may lag Google on the Web market, the software maker’s shares are worth $255 billion.

(Photo: Eamon Sullivan of Australia (C) swims to a world record next to Pieter van den Hoogenband (R) of the Netherlands and Brent Hayden (L) of Canada in their men’s 100 meters freestyle semi-final at the National Aquatics Center during the Beijing 2008 Olympics August 13, 2008. REUTERS/Wolfgang Rattay)