Need ideas on how to tell my son I'm pregnant

We're finally going to tell him next week and I am not coming up with any ideas of how to do it.

Any suggestions?

I would wrap a shoebox all nice and call it a wish box or something to that effect and ask him to write down all his wishes, 1 on each piece of paper. If he can't write, do it with him. Put them in a box and tell him that one will be granted from his box and it will appear under his pillow but don't tell him when, make it random so he checks under his pillow several nights building anticipation...then one night put the wish that will be granted 'I want a baby brother/sister' under his pillow like the tooth fairy does her thing....
or maybe write a letter to a leprechaun or fairy of some sort that grants wishes and then send him a letter back saying his wish was granted??
only problem would be if that wasn't something he wanted....

There are a ton of books in the bookstore on being a big brother and I think Sesame Street has a video out too. Once you tell him, those can be helpful to help him realize what an 'important' job he's going to have as a big brother....

does he like puzzles:?? Maybe get one of those puzzles you can print onto with a printer,, and have him put ti together and you can read it to him, or he can read it!!