It's hard for me to determine what was the last frequency I DXed, as when I'm DXing I usually do a lot of channel surfing, not staying on one frequency for long. (By contrast I sometimes see stories of DXers who will park on one empty or crowded frequency for hours at a time hoping something comes up.)
The last frequency I got a new log on, though, was 1290 AM, either last or Wednesday night sometime after 9pm (when Dave Ramsey on 840 KXNT had ended for the evening). I was listening to the religious station out of San Bernardino "Good News Radio for the Inland Empire", and kept hearing sports play by play and other sports talk. I was thinking hey maybe my first HSFB "STA" log? (see ABDX group on Yahoo for why I used that term.) I looked up the sports stations on Radio-Locator, but couldn't determine which one it was, though.
After a while, I heard CBS Sports Radio mentioned, heard a sportscast headlines sequence (the ones that are usually done every 20 minutes), then heard "The Source".
Turns out it was KCUB Tuscon, AZ. They're 1kW ND fulltime, I wonder why I haven't noticed them before? Btw also KAZA Gilroy, CA, was in and out, so I doubt it was aurora.