Equivalent to top -ua In older version of Mac OS X, maybe up to 10.6 or something like that, you could use top with -ua which accumulated CPU-usage and listed the process with most CPU-time at the top. This combination has since disappeared and I have been unable to find a replacement. Any ideas?

A nice addition would be if you could tell it to accumulate CPU-hsitory for e.g., 10 seconds, 1 minute or so, is that possible?
You're right, top has changed since 10.6 (Here is the man page for the top on Snow Leopard)

Now, to access to the accumulative mode you have to 


start top
type c to change the current mode 
type a to set the accumulative mode (and enter to validate the input) 


To sort by CPU time, use the -o option :  top -o time

About the second part of your question, I a bit curious. Accumulative mode counts the CPU time since the start of the mode. So I will do it for 10sec if you wait 10 seconds etc.