The Lego Education Blog recently released a PDF file with lots of useful information on how to program more efficiently to save memory (take it from an FLL comptetitor, memory can become a problem). View it here.
On the sixth page, there's a section about mini blocks - special versions of move, motor, sound, and display blocks - that will be released from the FLL Website during Fall. These mini blocks will cut down on memory usage while retaining some of the functionality of regular blocks. From the statements about it, I think they'll be really useful in comptetitions for maximizing memory capacity.