Adding a splash image to my blog before it auto-loads ?

Hello,

For tomorrow april’s first, I have an idea, but, honestly, I don’t know how it could be done, could I ask here, just in case ? 🙂

Simply, I want to redirect ALL my “first time of the day” visitors on my blog to an image that would be displayed to them during a few seconds, before the real blog is loaded as of usual afterwards.

(I thought of an animated gif, editing the “closed by the Feds” image as megaupload got it, replaced with “just kidding, you’re welcome as of usual, no worries” text.)

Would you know if there’s a relatively easy way to do it ?

I thought of the “warning : adult content” plugins, but they are not full-page image and they require clicking, while, in my case, I want an automated blog loading after a few seconds.

Thank you very much if you’ve got an idea ! 🙂