lattice question: independent per-row or per-column scaling?

Thanks for all the answers. I'll have a look at ggplot2. I'd seen the
possibility to set panel-specific limits via ylim, but I was in fact
looking for a switch to achieve non-global automatic scaling.

Given the fact that there is no built in provision for that, I take it
it's a functionality that isn't (considered) very interesting for most
lattice users, but out of curiosity, how difficult would it be to
implement it?

Fairly hard. The problem is that lattice conceptually separates the
array-like structure defined by the conditioning variables, and the
array-like structure defined by the layout. It makes sense to relate
them when you have exactly two conditioning variables (and the
corresponding layout), but not otherwise. For example, what you want
will not be sensible if you have a single conditioning variable with,
say, 12 levels, and you plot the panels in a 3x4 layout.

Unfortunately, this makes row/column scaling difficult to do even when
it makes sense. On the other hand, it should not be too hard to write
a general wrapper (similar to 'useOuterStrips' in latticeExtra) that
automates most of the tedious work.

-Deepayan