I am strictly a developer.
My wife is a paper based designer.
Sure, she can use a PC and does a lot of photography touch-ups editing for a a couple of wedding studios, but her real passion is in drawing/painting.
Whenever I do a job I get her to do the layouts while I am working on the business logic (process development etc)...
There is little sense in spending money on the creation of a tool, if you don't have the processes in place, first. I reckon 40-60% of my time is spent with the client ensuring there is management approval / a business requirement etc before I do a single line of code.
If someone want some really flash graphics / multimedia then I will call one of my business partners for that side of the project. there are very few people in the world that can actually be a super coder and designer... I use words of one of my mentors all the time when talking to people (fellow developers/designers and clients). "A Consultant is supposed to be a subject matter expert. They shouldn't need to ask anyone else."
There are too many technicians that are selling themselves as a consultant, but really shouldn't be. If you're selling your time/services as a web application coder, then you should know the ins and outs of coding for the web. (Of course if you don't know something, you make certain you learn it!!!) - But that is another subject....
- sorry... got a little carried away!