Ask Mr. Smarty Plants

I visited the website for the The Trial Gardens at UGA just to see if I could find anything that sounded like the plant you describe even though it has been about 15 years since you saw it.  As you probably know, the Trial Gardens do research on ornamental plants to study and develop improved cultivars for the horicultural trade.

Their webpage shows results for perennials and annuals that they have been growing in their gardens.  Their records online don't go back to 15 years ago, but I thought it was worth a look anyhow.   I looked in both the perennials and the annuals that they had been testing and looked for a name that sounded something like "Thiobana" and lo, and behold, I found a plant called Tibouchina 'Athens Blue'.  There were no photos with the report but I searched on the internet and found photos of the plant and it does have purple flowers and fuzzy leaves.  Here is a photo of Tibouchina 'Athens Blue' and here is a photo of another species of Tibouchina, Tibouchina grandiflora (Glory Flower).  Here is another photo and information from AlmostEden.com.   According to the Almost Eden site, Tibouchina grandiflora is native to southeastern Brazil and, as such, isn't really in our purview since our focus and expertise are on plants native to North America.  If Tibouchina isn't your plant, you might try contacting someone at the The Trial Gardens at UGA to see if they could help you.