Solution: let B 1A⊥y axis be in a, B2B⊥y axis be in b, and B3C⊥y axis be in C. Set equilateral △A0B 1A 1 △A 1B2A2, △ a2b3.

① In equilateral △A0B 1A 1, A0A=a, so B 1a= Atan60 = A, and the solution is a=0 (excluding) or A =, so equilateral △ A0B.

② In the equilateral △A2B 1A 1, A 1B=b, so BB2=btan60 =b b, and the coordinate of B2 is (b, 1+b), which is substituted into the analytical formula × (b) 2 =/.

③ In equilateral △A2B3A3, A2C=c, so CB3=btan60 =c C, and the coordinate of B3 is (C, 3+c). If you substitute the analytical formula ×(c)2=3+c, you will get c=- 1 (excluding) or c=, so the equilateral △ A3B3.

So the side length of △A2007B2008A2008 is 2008.