TIP: Freeing up memory

The next time you get one of those "out of memory" warnings, your first inclination might be to go and Purge the History (under the Edit menu, under Purge) which clears the history for all your open documents. However, if you hold the Option key (the Alt key on a PC) before you choose to Purge the Histories, it only purges the history for the active document, and leaves the history in tact for any other open documents. Hey, it's worth trying this first, to see if it frees up enough memory, while sparing the other doc's histories.