I owned about 3-4 TLD sites many Blogspots including one PR5 and 3 PR4 and many lower PR sites I M NOT USING ADSENSE anymore !!
No site yet, but currently have 2 PR3 blogs Will look forward to open a ebook downoading site in future...
I own 10 domains and I am currently developing several of them I hope to get one finished by the end of this week. I am anticipating it will be a good source of extra income.
You need to develop them then. Turn them into some money generating sites for you and get yourself some extra cash each month.