This topic may have been done before, and if so apologies, but the "Bad Endings" post got me thinking about how the writers frequently slipped in "new" (for the times) technology into the episodes.
As the years have gone by, of course, the "new" technology doesn't sound so new, but off the top of my head, I can think of these (dates just for context):
Home VCR in "Fade to Murder" (1976)
Compressed gas wine bottle opener in "Murder Under Glass" (1978)
DNA analysis in "Sex and the Married Detective" (1989)
Home fax machine in "Agenda for Murder" (1990)
Beeper bracelet in "Columbo Cries Wolf" (1990)
Micro recording equipment "Columbo Goes to College" (1990)
Cell phone in "Butterfly in Shades of Gray" (1994) (OK, maybe that one's a stretch)
Of course there are epsiodes that seem to be nothing but technogadgets ("Mind over Mayhem", "Playback", "Murder, Smoke and Shadows")
One that was sort of a twofer, which unfortunately I can't remember the name of (early 70's vintage), has Columbo trying to track someone down by checking the records at a large defense contracter. Behind the counter, there's a whirring computer with lots of blinking lights and a super efficient clerk who completely befuddles Columbo with her data processing capabilities. Then, he goes to make a phone call and is completely confused when he gets an answering machine. Now is that high tech or what?
I was just thinking of this one last night, but it was a case of SOMEONE ELSE, not Columbo, finding a piece of technology strange. In "Playback" (if I remember correctly), the hostess of the party is almost amazed by Oskar Werner's digital watch - not just the style of the watch, but the actual fact that it's DIGITAL. (I don't even know the episode well, but she was a sort of stereotyped - in a pleasant way - English woman, so I always remember her saying, "What a SUPER watch!") I don't know just when they started, or when they really took off, but it seems to me that 1975 is pretty late for someone to be amazed by a digital watch.
I'd wager that there isn't any episode that *doesn't* prominently feature some kind of interesting technology. To my mind, Columbo getting amazed by technology is an essential component of the general episode script. Perhaps I will compile a list indicating the technology featured in each episode/