I have found a program called nav4all.
it is located at
www.nav4all.com and is free currently.
It offers Turn by turn street level maps for your Blackberry 8800 as advised by the website and is free.
I have downloaded the software, installed the voice (there is like 100 different ones in different accents) and also downloaded the language pack for Engish.
Currently i have started the software and I am having issues getting the software to look for the inbuilt GPS chip in the 8800.
I have lodged a query with their support section and will advise If i can get this to work.
If this is the case and by the quality look of the software this is great - appears to be very similar to telnav or tomtom etc. It have done the searches with teh software and its fast and smooth. I will keep you posted once I can get the GPS to sync.
Let me know if anyone tries it and gets it to work in the mean time.
Sentinal