I need to top off my Delta and Continental accounts. Is there a minimum number of miles to be transferred? Can they be in any amount or do they have to be in set amounts; i.e. 1000 points? Is there a fee for transferring?

How long do the transfers typically take? Finally, how does the 20,000 points with 5,000 bonus work when transferring to Continental with 1:2 ratio? 12,500 miles?