cool build along dano...knife looks great sofar.
one word of caution to others, if you are unsure about the steel and heat-treating, DO LIKE DANO DID, and ask someone with a little experience. queching steel too quickly can ruin hours of hard work and even be dangerous (can violently rip itself apart).
there is a ton of old steel out there waiting to be recycled. lawnmower blades do work, bed frames as lance said, hay rake teeth, car springs, tie rods, old bumper jack handles, etc.
c'mon dano...you already got the torch, why not make a simple one brick forge and try hammering?