I was looking for a breadboard shield for my Leonardo (actually this version of it: http://imall.iteadstudio.com/itaeduino-leonardo.html) but I couldn't really find any with just a breadboard shield (no extra crap, apart from maybe jumper wires, but I don't really care about them). I noticed that the Uno pin layout seems very similar to the Leonardo layout, so I thought maybe shields for both would be compatible. Is this true?
It's true. They are the same for your purposes.
As an FYI, I found out the hard way that this shield pictured is pretty useless in spite of it looking pretty proto-friendly. There are no pads free for a std dip package. http://img1.banggood.com/thumb/large/upload/SKU027705/20120328175402845.JPG beware of duplicates on eBay. Stick with a Sparkfun or something where you can see what you're going to receive.
The pin arrangement on all the larger Arduino boards is physically the same for the core pins (some boards have many more of course).
Be aware that the SPI pins only comes out on the ICSP header on the Leonardo, pins 10/11/12/13 are not hardware SPI.
The I2C pins are not A4/A5 but pins 2/3 (there's also a separate pinout just for I2C duplicating this, so newer shields that know about this new pinout will work on I2C if they don't use pins 2 or 3 for other purposes.
So find out exactly what the shield in question uses and for what...
Thanks for your replies. Avr_fred, what do you mean by
There are no pads free for a std dip package.
Why would you want to solder a DIP package on?
euge64: Why would you want to solder a DIP package on?
After I've worked the bugs out of the prototype, I transfer the parts to the perf-board and solder everything in place.