If you have downloaded the freeware Irfanview, a wonderful header for a blog or an online page can be created by stitching photos together to create a panoramic image. So, if you are in irfanview, ensure that all your digial photos are the same height and preferably same width. (Nb ensure that they are jpg and not bmp. Rename them through irfanview when you save as. I found the size 380 x 285 is good for a start) Goto image>create panorama>add image and continue adding as many images as you desire to form the header. Goto Tutorial sheet link at http://ejourneys.wikispaces.com/using+images for instructions on using irfan view. This is then saved as a jpg image and can be resized to the correct wordpress size by going to irfanview image>resize/resample and keying in the correct height (try 770 x 223).
Note that text can also be added easily to the image. Goto edit>insert text into selection>key it in and choose colours etc.