<<No. Only machines with insufficient RAM to handle all processes NEED
the swap space. With 4GB of RAM, it's hard to make the system run out
of RAM even if you use KDE/Gnome and editing large photos with GIMP.

However, I'd still 1GB of swap space and use 'tmpfs' for /tmp.>>

This, running without swap if there is enough RAM is true for OSs like
SunOS. The memory managment for Linux IMHO is as follows, When every a
process is paged out, it is paged out to Swap. Only processes currently
executing is kept in swap. If I dont allocate swap to a machine, then the
processes cannot be swaped out. They will be retained in main memory to the
point that new processes will not be able to start.