I mentioned this site in a previous post but I wanted to write a little more because it is a awesome service.  I do not know the cost involved but you have to watch the demo because it is really awesome what they do ... all online!  I can only imagine the applications ....  specifically for realtors!  The send an appraiser out to measure land and improvements.  Then, the develop blue prints or plans for hardscape and landscape.  They work with the client on line to make changes to the plans ... in real time!  Then they connect the client with contractors to do the work.  I like it because it gives me work (as an appraiser).  But now clients do not have to spend top dollar for plans for small projects.  Check them out!  http://www.designscape.com