Keter,

Do you know of any place that sells prefab wooden T's?  I checked the local home depot and some other stores but nothing fit the bill.

Thanks in advance

I didn't think about the moisture issues and I'll probably need to pick up a dehumidifier for the room just to be sure.

I think the T' wood blocks would be a simple and functional solution to displaying cards and I can take a blind eye to the content of the cards and let the colors lead to interesting patterns (as per chapinerika). 

You're right about the bats, I'll have to float one around the room until it fits.  I want to be careful so that I'm not making my basement look like TGI Fridays or some other chain restaurant.

I apologize for not posting pictures as we are STILL moving from our old house to the new one.  The wife has me picking up things that would be in the garbage if I had it my way.

I promise to have pics put up tonight when I get off work. 

Basements can be problematic for collections...moisture, poor air circulation, artificial light, mold, dust.  I would recommend sealing all of your really valuable or vulnerable articles in plastic cases at the least, and be sure you know and avoid any areas that tend to be prone to moisture...this is not always obvious in a new (or recently renovated) house.

I've seen a wall done with vertical wooden Ts to create slots into which plastic card cases were dropped.  This created wall art and prevents casual theft.  (Somebody ripping up your wall would be pretty obvious.)  You could do something similar with any same-sized plastic case, such as ball cases or t-shirt frames.

A cheap way to display t-shirts or jerseys is to stretch them over artist canvas stretchers (if you use stainless steel staples you minimize damage) or to use dowels to hang them by slipping the dowels through the arms.  Fold in the sleeves to maximize hanging room.  If the logos are all near the top of the shirt, consider tying the bottom with a ribbon to create a pennant effect.  Hang these high to minimize the chance they might get splashed with food, drink, craft paints, etc.

Look for unexpected places to display the bats, like hanging from the ceiling (horizontally, not where they might use heads for practice) or tie wrapped to shelving uprights or underneath shelf fronts.  One weird (and probably expensive) display I remember turned stair risers into lighted display cases.  The cases had plexiglass fronts to prevent breakage.

If you're into a particular team, you might want to use their colors to upgrade your paint scheme!  Because this is a basement, I would be careful with the leather accents, such as using it on barstools or to cover small nooks.  There are printed ultrasuedes out there that are durable, easy to work with, and mimic almost any leather pattern.

Have fun!