Don't think it can be done in an RCO.

Might be possible in a PRX, but it doesn't exactly sound that simple.  There's probably a value which controls the time the volume bar stays active once you press the volume.  From what I've seen, the PSP tends to use floats to store the number of milliseconds, so if anyone's interested, they could try that.

EDIT: it's 0x14F8 on my 3.10 impose_plugin.prx.  For other versions of the PRX, search for the value 0x44F40000 (2000₁₀) and replace it with something large, like 0x4F800000 (2³²₁₀).  There should be multiple instances of 0x44F40000, on mine, the first one is the one you want.
One issue is that you need to press the volume button for it to show.  Once shown, it'll stay there, even through sleep.

(This post was last modified: 28/07/2007 07:12 PM by ZiNgA BuRgA.)