The 3-5 day period is available in exchange with bank transfers only. If you trade with individuals (or even services) that use PayPal, Skrill, Neteller etc. You wouldn't face any issues receiving your bitcoins instantly (PayBis, Virwox, BitPanda are an example), the fees may be high compared to whatever you are using now though.
The rates you get will not be that good either.
OP, how much are you planning to buy? If the amount is under $500 then do what OmegaStarScream suggests. But if it is more than that, I believe the 3 - 5 day wait for the wire transfer to go through will be worth it. The fees are less and you buy Bitcoin at a better price in a top exchange like Bitstamp. Avoid the smaller ones.