Lay them all out in a straight line. Attach camera to rc car. Drive car past pics. Basically Google streets but for your pics XD /s

Lots of great suggestions here though.

Cheap. Fast. Reliable. Pick two.

The easiest, quickest, and best way I found to scan thousands of photos was to purchase an Epson FastFoto scanner. You stick a whole stack of photos into it, it scans them one after the other amazingly quick, then you stick another stack in and keep going. I did this with boxes of old photos of every size, some of which I literally had to cut out of photo albums. There are options for scan quality and resolution. It helps tremendously to have your photos organized for how you’d like to store them, so for instance have your 1989 Grand Canyon photos together so that they can be named and numbered as they are scanned. It will even scan the back of the photos if you have writings or labels you want to preserve. This might not be the cheapest option, but its fits your other criteria perfectly.

I think you have three choices that represent different mixtures of your ask.

1. Just scan them. Most phones have either a built in or app-available function to take the burdens out of scanning documents and photos. With thousands, you’d be talking about stretching it over a few weekends, maybe, but you could do it while watching tv or listening to an audiobook.
2. Scan and edit. You can buy a higher end scanner that would allow you to have more control over the quality of each scan. You could also use photo editing software to color correct or make whatever edits to the hopefully only dozens of photos you really care about, while leaving the option to do so open if you suddenly need that pic of Aunt May at the picnic.
3. Pay a pro to do it. You can find services that are all over the place in price and quality (basically because they’re centered around either option 1 or option 2). If you go with a higher end place, you’ll get people with a much higher skill set in scanning equipment and using photoshop then you. Lower end is basically lie the clerk at the UPS store that sends faxes. I’d recommend against sending any really important ones through the mail, though, so this again might be where you’d want to sub-select on the ones you really want done well and the others that you’d only mostly want to keep.

If they're in good condition, you can get scanners with document feeders and software that aligns the scanned photo. No idea on the cost though.

You can scan them yourself, and lots of scanner software lets you scan multiple photos at a time and then separate them in the software. However you do it is going to take time though.

Go to a library, some have scanners with feeders that will scan to a flash drive.