Took a quick look around this forum to see if there was anything about syncing with Yahoo and couldn't find anything so here you are:
I have a personal 8700g on T-Mobile UK. I bought a new personal laptop computer recently and chose not to get MS Office as there are now alternatives to this such as OpenOffice.org: Home
. So I don't have Outlook. I was interested to know if/how I could back-up & manage my BB contacts, calender etc without Outlook and found that the latest BB Desktop Software download from the T-Mobile UK BB site is 4.2.2 12 which includes a "sync to Yahoo" option for the contacts & calendar.
Whole thing worked very quickly & smoothly, I was really surprised!