Align several columns into 1 columns

[Kel12]

I have 3 columns:
-------------------
a D g
b E h
c F

and would like to have them aligned into 1 single column:
--------------------------------------------------------------
a
b
c
D
E
F
g
h

Any suggestion for what i could best use for this purpose.
In reality, i have about 200 columns with different number of rows.
So i need to align smarter than manually.

[Special-K]

This will work for your example

in D1
=INDEX(A$1:C$3,MOD(ROW()-1,3)+1,QUOTIENT(ROW()-1,3)+1)
and copy down

Since you have 200 columns this solution may not work, you may need to change ALL the 3's int he formula to however many columns you have
This also assumes that all columns have the same number of rows filled in.