Simplified Spell Durations (not yet used, reconsidering)
Generally speaking, the above makes spells more long-lasting at lower levels, and the reverse at higher levels.
It also means that if you cast a spell with a duration of x hrs/level (or longer) twice during the day, I'll consider it to be in effect at all times during the day. (I.e. if you want an x hrs/lvl spell to be in effect at all times it's probably easiest to just subtract two cast spells/wand charges/whatever first thing in the morning.)