Edinburgh to Glasgow by Towpath
It is possible to pedal all the way from Edinburgh to Glasgow alongside the Union and Forth and Clyde Canals, taking in the Falkirk Wheel along the way. I haven't done this yet - perhaps one day I'll get a train through to Glasgow with some of the kids and cycle home.
At the Edinburgh end the route starts near the bottom of Leamington Terrace, just off Fountainbridge at Edinburgh Quay. The towpath is narrow in places and is shared with pedestrians, often walking dogs, so care is needed - use of bell or other gentle warning device is recommended. It also goes under a number of bridges which are blind, so again care is needed. The first part of the route is now well surfaced. The route wends its way past Harrison Park and across a couple of aqueducts - the second of which crosses the Water of Leith and is narrow with little room for passing people or bikes coming in the opposite direction. The Water of Leith Visitor Centre is below and is worth a visit in its own right. Looking across you can see a viaduct carrying the railway to Glasgow.
I have cycled as far as Ratho and back - it's not really a route for road bikes being rather bumpy in places. There are also a number of "gates" - presumably designed to discourage people from taking motorbikes along the towpath.