remove "quiet" and "rhgb" from the boot options (or press escape during plymouth boot screen)
The bar is there when it's not working properly, the "charge" theme is supposed to show off what a great boot system fedora has
You can install other themes like spinfinity, try ''yum list plymouth-theme*', and do something like
yum install plymouth-theme-spinfinity
plymouth-set-default-theme spinfinity
/usr/libexec/plymouth/plymouth-update-initrd
(That's for F11, might have changed in F12 with dracut)
Edit: No, it hasn't changed in Fedora 12, same instructions (I think you can do steps 2 & 3 in one go with "plymouth-set-default-theme spinfinity rebuild-initrd")