I have 3000 with my nikon 4300 and about 600 with my Nikon D70. I had my d70 for about two or three months so I am still getting use to it and experimenting with it. I had my Nikon 4300 for about a year or two.
Mostly it's by file number, no? I was just guessing on mine - I'm up to folder 206Canon and my image numbers are like 0604, so I'm guessing 100 per folder, 206 folders....20600 images?
Not sure if Olympus does the same.
My last image taken (today) is PA183623.JPG
The PA has to do with year (at least the A part - October. P9173085.jpg was Sept 17th, file 3085) What the P is I haven't been able to find out. Last 4 numbers is sequential number for ?
?
2,244 since July 20, 2004. Approximately 24 pictures per day, if I did the math right. Of course, 350 of those were at my cousin's wedding, another 200 or so at a local street fair, around 250 on vacation at Niagara Falls...