There are a large group of polling service I find flawed or unreliable due to inherent bias, and Gallup is one of them.
By that, though, what I mean is that I don't trust the absolute numbers. Guiliani at +12% nationally? Ridiculous. That aside, trends can be important. Even if, for example, I don't necessarily believe their number for Romney is correct, the fact that he's trending down is still important to note.
“Polls are unreliable”
You are right on target. The only one that I think is fairly reliable is Rasmussen. The rest are in varying degrees “push polls” designed to try to influence the electorate. The fact that Gallup has shown an upswing for Fred means that FOX will be issuing a new poll showing their boy Rudy widening his lead to 98-2 over Fred in about 3...2....1...
The problem with push polls is they are not effective in a general election and are completely ineffective in a Primary. As the election draws closer they will show Fred’s lead so they do not lose credibility totally. At this stage, they are not to be trusted.