Updated in the year 2009
To make it easy for fast conversion;
1000 Pesos is about 0.50 US dollar
1 US dollar is about 2000 Pesos
1000 Pesos is about 0.33 Euro
1 Euro is about 3000 Pesos

Here follows all the money of Colombia starting with the biggest value.

50000 Pesos is Cincuenta Mil Pesos equals about 25,=US$ or 17 Euro

20000 Pesos is Veinte Mil Pesos equals about 10,=US$ or 7 Euro

10000 Pesos is Diez Mil Pesos equals About 5,=US$

5000 Pesos is Cinco Mil Pesos equals About  2.5 US$

2000 Pesos is Dos Mil Pesos equals About 1,=US$

1000 Pesos is Mil Pesos equals About 0,50US$

Coins of 1000         500           200              100           50          20          5      Pesos

1000 Pesos is about 0.50 US dollar in 2009
1 US dollar is about 2000 Pesos in 2009

The 1000 Pesos coin is out of rotation because there were too many false coins.
The 5 Pesos coin is not very much used.

The 50000 and 20000 bills might be hard to get change for on the street, small stores or in Taxi's.

Have a look at these beautiful stamps

YwamMedellinColombia
WebDesign Daniel Huisman