Franco kernel has all sorts of volume enhancements baked in that you can configure. If you're on basically any of the newer roms you can flash Franco's kernel and adjust to your liking.
You might need his paid app in the market to configure however... i think it's like 2 dollars. Maybe someone can confirm if you need the app or not?
Sure man. there's at least 3 options for adjusting the volume. And franco's kernels generally work very well aside from the sound enhancements, as well.
As far as ROMs, there are some that have the volume raised to a more usable level without needing a specific kernel. Off the top of my head: Bugless Beast, AOKP, CyanogenMod (and any AOKP or CM based ROM, which is most of them).
You guys got volume hacks? Man that would be sweet on the NS4G versions of ICS.. We have one ROM I know of that has a very noticeable volume increase which is CM9 Kangs otherwise we suffer from lack luster low ringtones/notifications as always from our Nexus's.