Flicker a la 24

[ando775]

I'm trying to create a flickering effect on a title to resemble the opening of the tv show "24" when the 24 appears on screen like a digital readout and flickers until it's reaches full brightness. I messed around with a couple of filters and had the most success with Tone Medium, but it still doesn't work quite right. Has anyone tried to do a similar flickering effect? THanks.