Can anyone share the cases of when they have used sqlite :memory: databases?

I was able to use APC in the past which was fantastically fast, but I have never thought of using sqlite::memory: before.

I realise that if the server loses power then everything is lost, but I have a few thousand records I'd like to use - a bit like a readonly 'in memory array' so data loss is not an issue for me.

Once loaded in memory is this database then really available to all connections?

How do I make sure the database is loaded in memory whenever the service is restarted?

Any experience good or bad would be welcomed.

Thanks