Parallax (www.parallax.com) is selling breadboards that have 6 (yes 6)
contacts on each side of the center gutter instead of the usual 5. I
just discovered this – I don’t think I’ve ever seen one with anything
other than 5. This provides more working area on either side while
still following the more traditional location for the chip/boarduino.
I like these boards, but they don’t work with things like power supplies
that plug directly into the power rails on either side (since the rails
are farther apart).
Another nice thing about them, in addition to the 6
contacts, is that the power rail contacts line up directly with those in
the main breadboard – they are not shifted the way they seem to be in
most breadboards these days. Of course, to make up for that they put a
gap in the middle and split the positive (red) strip in half. This
makes it easier to use multiple supply voltages, but you lose more
contacts bridging the two halves when you’ve only got one supply.