We usually fly on a Tuesday or Wednesday because not only do the flights tend to be cheaper, but the airports are less crowded. US Air always has daily non-stop flights from Philly to MBJ, so that is not an issue. The only downside is that this forces me to use an extra vacation day (if we stay from Saturday to Satuday, then I need to take 5 vacation days - If we stay from Wednesday to Wednesday, then I need to take 6).