Hey, I was senior captain of my hs track team this spring. Here are some things my team (girls team) has done this year and in the past. (not to be a creeper but i clicked your username and from your email i'm guessing you're a girl? lol just because a lot of these wouldn't work so well for guys, so if you are a guy you'll probably have to ignore most of these.)
-lots of pasta parties. play music
-buy plain t-shirts and either tie-dye them or paint them with fabric paints to make team shirts. you can put your nicknames, etc. on them and wear them at meets.
-"color wars" divide the team up into small groups and assign each a color. Then on a specific day, everyone has to come to practice wearing only that color. The more outrageous the costumes the better. Prize to the group with the best outfits. We have so many great facebook pictures from that day lol.
-decorate some hair ties with ribbons in your school colors, you can write "XC 09" "[team name]" etc. on the ribbons in fabric paint. Then you can wear them at meets.
-French braid each other's hair the night before a meet
-Before a big meet, everyone draws a teammate's name from a hat. You write a letter to that person encouraging them, which they open the next day on the bus ride to the meet. Works best with small teams so you actually know the person you're writing to
...yeah i'm sure a lot of letsrun posters will think these are really dumb and make fun of them, but they worked great on my hs girls team and they were a lot of fun. Good luck! :)