Iranian President Mahmoud Ahmadinejad was the main star of a concert today.
As CNN and others noticed, he ordered his experts to create 20% enriched uranium instead of the 3.5% enriched uranium they're developing now.
Basic texts about the enriched uranium may explain you that the percentage refers to the fraction of the U235 isotope. The natural uranium is "less than 1% enriched" - 99% of the stuff is the dominant natural U238 isotope.
The slightly-enriched and low-enriched uranium - such as the 3.5% enriched uranium developed so far - is actually OK for power plants and it even has some virtues. However, it's much better to use a highly-enriched uranium for the bombs. More than 85% enriched ("weapon-grade") uranium is standard for nukes. The first uranium bomb, the Little Boy, used 64 kg of 80% enriched uranium.
However, 20% is sufficient for an inefficient weapon: it's called "weapon-usable" uranium. That's exactly what Mahmoud ordered today. You may ask why he did it. Perhaps, he wants to create more expensive nuclear power plants because he realized that he has too much energy in the oil? ;-)
It has surely nothing to do with the weapons, right? I am afraid that bombing of Iran is what TRF has to recommend at this point and the presidential palace should be among the targets, too.