I've not hit the magic billion but I have done 100's millions.

I used to take the production server down for a morning when I did it.

My approach was as follows

• Calculate the size of the table to be copied.  See BOL and in the index type "calculating table size" the top three entries are the valid ones.
• Expand the target database by that size.  You don't want the database autoresizing when this baby runs!
• If you use trunctate log on checkpoint then switch it off.
• Expand the transaction log, again you don't want it auto-resizing.
• Drop all indices/constraints/primary keys/triggers on the target database etc
• Use DTS Wizard to build and run the insert.
• Rebuild indices/constraint/primary keys/triggers etc.
• You may want to truncate the transaction log and DBCC SHRINKFILE it.

I'm a bit rusty on the process because it is something that I did in my last job, over 4 years ago but I seem to remember I had to expand TEMPDB for the reindexing part of the process.  Again, you don't want autoresizing to take place whilst the job takes place.

I also had to kick everyone off the database server when I did the process.

The choice was stay off the server and have everything back by lunchtime, or stay on the server and this urgent data might be ready next week.