I've come to think of every lock I buy being part of the price we pay for crime; Just needing a lock means you're already a victim.
I try like hell to make my stuff less valuable to thieves. Here are some of the things I've done:
-As mentioned above, I ID my tools;
-I paint them a distinct, plain color. This not only marks them as mine, but makes them lose that shiny new "steal me" look, and makes them far less pawnable;
-If I had the balls, I'd paint them pink!;
-Many of my tools are of a different brand than what everyone else has (I'll never forget the guy who told me to get rid of my "junk" Starret and buy a Craftsman!); and,
-I have locks, etc., that are decent enough to require serious effort to defeat.
Last, but not least, I refuse to patronise flea markets, "tool stores" operating from the trunks of cars, and any situation where I have the slightest doubt as to the source of the items. I will not help a thief by providing him with a market!