I went to the US Open yesterday with Mike S from the Brooklyn Tennisopolis group.
He had a extra Day Session ticket available, so we made a day out of it.
We saw Nikolay Davydenko vs Dudi Sela and also Jo-Wilfried Tsonga vs Santiago Ventura.
I think Ventura is someone to keep your eye on.
The sun was pretty intense in the stands. We could only watch a set from each match before had to scramble for shade.
We also watched some Mens & Womens doubles being played on the side courts.
Fun to watch because your standing right next to the courts at player level.
A bit of advice.
If your going to the OPEN, use the South Entrance. The line is much shorter.
Also, if you have an AMEX card, bring it. They are giving away free ear type radios to listen to commentary. You can also borrow a small TV to watch other matches from the stands. The card also comes in handy for buying those $9 beers.