What you’re looking at is a snapshot of a Google Trends chart comparing the number of times the word  “iPhone” appears in a Google search request with the words “Palm” (PALM), Research in Motion’s (RIMM) “BlackBerry,” Microsoft’s (MSFT) “Windows Mobile” and Google’s (GOOG) “Android.”

The full chart — going back to 2004 — and the color key are pasted below the fold. Or you can click here to recreate the chart on your Web browser.

Google Trends is a powerful tool. It has been used, most famously, to monitor influenza outbreaks by tracking flu-related Google searches — a epidemiological early warning sign that turns out to be more prescient, by two weeks, than the U.S. Centers for Disease Control’s surveys of 1,500 hospitals. (Google explains its methodology here, with a link to an article in Nature.)

You can do a Google Trends search on anything. Blogging pioneer Dave Winer ran a series recently comparing “Twitter,” “Web 2.0” and “RSS.” Twitter won that clap-o-meter competition hands down. Twitter’s micro-blogging tool been a hot media topic for more than a year, but Winer’s Google Trend search shows that it’s been on fire since January.

Let’s take a closer look at the iPhone chart, below the fold.

You can see right away why it’s so hard for Apple’s competitors to be heard above the din. Those spikes (A, B, C, etc.) marked by randomly chosen news articles are triumphs of event marketing orchestrated by Steve Jobs and amplified by the writers — including this one — who follow his every move.

The timing of most of those spikes are self-explanatory. June 29, 2007 was the day the first-generation iPhone launched. Sept. 6 marked the day Apple lowered the price. The iPhone 3G went on sale on July 11, 2008.

But even adversity plays into Apple’s hand. The iPhone was first unveiled on Jan. 9, 2007, but interest in the device spiked two days later, when Cisco (CSCO) sued Apple for over the iPhone trademark (the two companies eventually settled out of court).

How can RIM, Palm and the rest compete? The launches of the BlackBerry Storm and the Palm Pre barely register on the chart. In fact, the Palm trend line is almost certainly inflated by searches related to “palm trees,” especially in cities with a lot of them, like Miami, Los Angeles and Irvine (see red “Palm” bar in the chart detail inset).

It remains to be seen whether Apple can continue to dominate the buzz with Steve Jobs out of the picture, at least temporarily. In the Google Trends chart comparing “Steve Jobs” and “Bill Gates,” the two computer celebrities switch places several times over the years. Steve Jobs searches shot up when his health problems were in the news, but since he took his medical leave, the two lines have crossed and now Gates is back on top. See here.