Regarding on and upon
It's a common mistake made by a lot of writers: using "upon" when plain old "on" is called for. It's not the worst mistake you can make, but once you're aware of the difference, it's an annoyance you'll stumble on a lot. I came upon---I mean on---the issue while reading Lyn Dupre's excellent "Bugs in Writing: A Guide to Debugging Your Prose."
"On does not usually require any help from up, and you should never waste extra letters by putting them
Good: "Once upon a time..." Ugly: "Maria and Geoff decided upon a control technique that used agendas in a separate element class."
Ugly in the NY Times: "Immediately upon leaving the White House on Wednesday night, Mr. Cantor and his aides offered their description of the clash."
Another clunker: "With regards to..." and "Regarding such and such..." I don't know of a single example showing that this is good writing, unless it's a salutation in a letter: "With best regards..." Mr. Micawber is a little slack on the issue: "The most extreme critics consider them all circumlocutory and suggest that you replace all of them with about, on or concerning." Just so. Call me an extremist, but I can't think when even "concerning" is required. "On" or "about" are much better, and if they don't work, rewrite the sentence.
Chronicle writer John King provides a good/bad example:
The two-hour face-off won't be a formal debate, but it's a venue to nudge the candidates beyond platitudes with regards to everything from historic preservation and height limits to the balancing act between the push to create substantial new housing within the city...(emphasis added)
Why not simply "in" the city? Adding "with" to "in" here is pretentious. Plain old "on" or "about" would have been a lot better than the verbose "with regards to."
Whoever wrote the hed---I bet it wasn't King---for his column got it right: "Mayoral debate on building."
Strunk and White are good guides on writing, as is George Orwell.