I also got a new 01 SE just a few weeks ago and have been making a few mods (maybe these mods would also interest you).
-- Replaced the stock hubcaps with a nice set of American Racing wheels.
-- In the process of upgrading the stereo system. Got a killer deal on a amp from www.ubid.com ($29 for a 400 watt, 4 channel Profile Clarus series). Also got a set of 6.5" CDT components for the front with CDT 6x9's for the rear (off carudioforum.com's website for $175 total!). I figure $205 for upgading part of the the stereo system isn't too bad. If I see a great deal on ubid I may even swap the head unit...who knows.
Now for engine mods....there really isn't much out there for us right now. K&N filter replacement is a popular, but controversial (search K&N at goggle.com and see what I mean). Currently there are no aftermarket chips and the aftermarket air intake mods were mainly the labor of one person in this forum who last I heard doesn't do this anymore.
Maybe in the coming years we'll see more aftermarket mods for our ride. Who knows.....