Thoughts about Inspiration and Influence

On my travels around the web, I come across lots of creative work which inspires and influences me, but this always worries me slightly.  While I love to look at and admire the work of others, I want my own ideas and work to be as original as possible - truly my own, and I'm always worried that if I spend too much time looking at what others are doing, my own work will be influenced more than I would like.  Now I know that this is ridiculous.  No man is an island, and nobody's work can ever be 100% completely and utterly original - it will always build upon what they see around them.  Even the greatest artists are influenced by the work of their forbears and contemporaries to greater or lesser extent, and it informs and helps develop and improve their work.  So I should be able to do the same.  But where does admiration or inspiration end, and copying begin? Sometimes it can be a fine line.  For me, influence is about perhaps taking an element of someone else's work, and using it to change and develop your own - that element will itself, simply by being placed in a different context, change, develop further and look different, especially as time goes on.  Sometimes it is just a matter of experimenting with a new technique, a technique which you may find you love and adopt wholeheartedly, or one which you may ultimately discard, but which will have led you on a new journey, learning new things along the way.  At other times it may be just a colour combination.  I suppose as long as the influence is just a starting point for creating something new it shouldn't be a problem.  Copying the art of the great masters for example has long been acknowledged as a valid way of learning about the practice of art.  Even though I know that all this is natural and good, I still feel guilty if I am inspired to try something that someone else has done first.  It even concerns me sometimes that I may start subconsciously copying someone else's work, something that I've seen and admired, but forgotten about.  Perhaps I'm a little paranoid about it, but I'm going to have to get over it because otherwise I'll never do anything!