http://www.ewg.org/cellphoneradiation/Get-a-Safer-Phone

The most dangerous phones - from higher radiation to lower:

HTC Android myTouch ---------- 1.55 W/kg H!H!H!H!H!
Blackberry Curve 8330 --------- 1.54 W/kg H!H!H!H!H!
Apple iPhone 3G ----------------- 1.39 W/kg H!H!H!H!H!
Samsung Omnia (SCH-i910) -- 1.31 W/kg H!H!H!H!H!
Nokia 5800 XpressMusic ------- 1.29 W/kg H!H!H!H!H!
Apple iPhone 3G S -------------- 1.19 W/kg H!H!H!H!H!
Palm Pre --------------------------- 0.92 W/kg H!H!H!H!
Nokia 7510 ------------------------ 0.84 W/kg *I*I*I*I
Nokia 5610 ------------------------ 0.81 W/kg *I*I*I*I
Nokia N900 ------------------------ 0.80 W/kg *I*I*I
Nokia N97 ------------------------- 0.66 W/kg *I*I*I
Samsung Impression (a877) --- 0.35 W/kg *I*I

EDIT:
Added N900 and N97. Thanks Benny1967 (according to sar.nokia.com)

According to the FCC (link), no link has been shown between RF radiation and cancer.

As a physicist, I find the numbers telling. To cause cancer, the radiation would have to damage a DNA strand. The photon energy of RF radiation at 850 MHz is 3.5 micro-electron-volts . The energy of covalent bonds, the bonds between molecules in DNA, are on the order of 1 electron-volt--about 300,000 times the energy provided by the photon. This means that the photons from a cell phone can't break the bonds in DNA. Photons can't "gang up" to break the bonds--it just doesn't work that way.

Even at such low photon energies, it is possible for damage to be done to biological tissue with high radiation power, due to thermal heating (that's how a microwave oven works). None of the power absorption levels listed above, however, are high enough to do anything. In fact, they are roughly comparable to the amount of heat a normal person generates. If the average person consumes 2000 calories (actually kilocalories) a day, and weighs 80 kg (~180 lbs), then their heat generation is 2000 kcal/(24 hours)/(80 kg) = 1.2 W/kg (thank you Google Calculator).

Sorry for the rant, but after hearing a cancer specialist on say on TV tonight that cell phones have no proven connection to cancer I wanted to try running the numbers. If you really want to worry about what health risks your cell phone has, ask yourself how often you use it while driving.

I've read at (approximately) 7W/kg or higher, it can induce behavioral change to the (animal) subjects in some tests.

Now that's an interesting chart. May I add three more varlues:

Nokia 6110 Navigator: 1.16 W/kg (the one I'm currently using)
Nokia N900: 0.80 W/kg (according to sar.nokia.com)
Nokia N97: 0.66 W/kg (according to sar.nokia.com)

At those levels you might start feeling the heat--which would probably be responsible for any immediate behavioral change. Was it an immediate short-term change or something delayed or long-term?

Nokia N900: The highest SAR value reported under this standard during product certification for use at the ear is 0.92 W/kg and when properly worn on the body is 0.82 W/kg (Nokia Source)

Thank you baksiidaa for your interesting post! I always try to explain the (non-)problem to non-scientific people using the analogy of light: A cell tower has a "big lamp", the mobile phones have "small lamps" signalling to the tower. This aren't floodlights, but only very small "LEDs" :-)

Ok, I will update the chart, thank you for the info.

New N900 Tag Line: "Causes Less Cancer!"

You could also mention that cell phone photons have a millionth of the energy of visible light photons.

Now that's funny. Which information you get from sar.nokia.com depends on the country you select from the drop-down. ("location")

I, of course, selected Austria. So what they tell me is:
If you select USA, you get the same paragraph as above, plus an additional one that obviously refers to some FCC testing procedure. It reads:
(Cool. So you have three values in the U.S.)

Anyway... I don't care a lot about local peculiarities, so I'd rather take the ICNIRP value for comparison.