The Adafruit Raspberry Pi T-Cobler allows you to connect a Raspberry Pi to a breadboard using one ribbon cable. The ribbon cable connects to the top of the T, and the verticale part plugs in to the breadboard.
The slightly older version isn;t T-shaped and I found the ribbon cable kept getting in the way.
There are also a few cheapper versions now appearing.
|Adafruit Industries 2028 ACCYPI T COBBLER GPIO BREAKOUTPI 23W 40 PIN GPIO C|
End Date: Wednesday Dec-25-2019 4:59:31 PST
Buy It Now for only: $7.95
|Adafruit Assembled Pi Cobbler Plus Breakout Cable ADA2029|
End Date: Saturday Dec-28-2019 2:16:15 PST
Buy It Now for only: $13.08
|Adafruit Assembled Pi T Cobbler Plus GPIO Breakout ADA2028|
End Date: Saturday Dec-28-2019 2:17:58 PST
Buy It Now for only: $14.68
|Adafruit Pi Unassembled T Cobbler Breakout Kit for Raspberry Pi ADA1105|
End Date: Friday Dec-27-2019 5:57:12 PST
Buy It Now for only: $12.28
|Adafruit Pi T Cobbler Plus Kit Breakout for 2x20 Raspberry Pi ADA1989|
End Date: Saturday Dec-28-2019 2:15:43 PST
Buy It Now for only: $13.88
|Adafruit Pi T Cobbler Plus Assembled GPIO Breakout for Raspberry Pi A+ B+ Pi 3|
End Date: Monday Dec-16-2019 3:31:43 PST
Buy It Now for only: $24.67