Okay, after looking around and checking the libs that come with the 
windows installer of ruby 1.7.2-4. I see that it comes with both expat & 
xmlparser already installed.

Cool I thought and tried to use the RubyPhoto app and got the following

J:\website\pics>i:\development\ruby\lib\ruby\site_ruby\ruby_photo.rb
I:/development/ruby/lib/ruby/site_ruby/findbin.rb:23: warning: 
parenthesize argument(s) for future version

<!!! at this point a dialog appears on screen and states:

ruby.exe - Unable To Locate Component : This application has failed to 
start because libexpat.dll was not found. Re-installing the application 
may fix this problem

!!!>

I:/development/ruby/lib/ruby/1.7/xmlparser.rb:5:in `require': 126: The 
specified module could not be found.   - 
I:/development/ruby/lib/ruby/1.7/i386-mswin32/xmlparser.so (LoadError)
from I:/development/ruby/lib/ruby/1.7/xmlparser.rb:5
from I:/development/ruby/lib/ruby/site_ruby/myxml.rb:1:in `require'
from I:/development/ruby/lib/ruby/site_ruby/myxml.rb:1
from I:/development/ruby/lib/ruby/site_ruby/config.rb:1:in `require'
from I:/development/ruby/lib/ruby/site_ruby/config.rb:1
from I:/development/ruby/lib/ruby/site_ruby/album.rb:6:in `require'
from I:/development/ruby/lib/ruby/site_ruby/album.rb:6
from i:\development\ruby\lib\ruby\site_ruby\ruby_photo.rb:8:in `require' 
from i:\development\ruby\lib\ruby\site_ruby\ruby_photo.rb:8

J:\website\pics>

Now, I can find xmlparser.so. Its exactly where indicated above, but 
there is indeed no libexpat.dll.

Is it missing from the distro? is it built into mswin32-ruby17.dll?

Rob