Hi Rochr,
a quick way would be to have image1 on one layer, open image2 and drag it onto the image1 file. This will create another layer. Resize your canvas to the width of both pieces together. Move the second layer to the right to where it just overlaps the first image and select the eraser tool, choose a small to medium brush and set the opacity slider down abit. Erase part of the overlap to make the hard seam less noticable.

let me know if this helps,
:)
retrocity

Thanx a lot!!! Worked like a charm! But how can i do a straight line with the eraser tool? I thought it was by holding the shift-key while i erase, but i didnt work...

Rochr,
to make a straight "erase", click at the first point and let go of the mouse button. Move to the second point, hold down the "shift" key then, and click the mouse again. This will erase between these two points.

:)
retrocity

If it has to be horizontal or vertical: Click&hold and then drag with the shift key pressed also results in a horizontal, vertical or 45 degrees diagonal line. I add this because pressure sensitive pens also change the line thickness according to the pressure of the second point. As a result making retrocity's method a bit hard to control.

I use the polygonal lasso tool then select inverse . Meaning what you want to not erase you outline then inverse the selection to erase what you dont want. I would also add for you to use the clone tool to clean things up a bit adding parts were they are needed to get a better overal design . So that the joins are not so crisp and are more flowing.