Thanks Andy. I did discover that source shortly after my earlier post. I got my mbed module two days ago, so I'm a real noobie.
I am so used to having a debugger available that I sort of panicked at its absence in the mbed IDE. I also struggle a bit with little things like an ain.read_u16() taking 72 microseconds when I know that it can be done in 5 microseconds (or even less if BURST mode and interrupts are used). But the idea of mbed is as a platform for quick prototyping and is not meant to extract the last bit of performance from the underlying hardware. My early experiences indicate that it is meeting those goals superbly.
So, I'm going to adjust my attitude and work with mbed as is; use it to prototype designs, and if performance becomes an issue, I will develop my own libraries that better (but more rigidly) exploit the LPC1768.
Has anyone gotten the code red rools to sucessfully build a project using the mbed libraries?