Joomla 3.0 is coming in mid-September are you ready? If you have not updated your 1.5 version to 2.5 I can help you with that major web development undertaking.
The big difference between 1.5 and 2.5 is the database. The database gets a major overhaul which is the most significant change. What does that mean? It means you will need to install 2.5 versions of all you extension, if they are available, or find replacements.
So far I have not had any problems finding a new version of the extensions I have recommended to my clients. Which means that I do not have to rebuild any or redo any of my previous work thus a faster turn around to go live.
Generally it takes several days to convert a site, install and check to make sure the converted site is ready to live and replace the old. Contact me if you need help or want me to handle the whole project.