what can you do to make it funner? lots of stuff! depends on how much you want to spend.

you can change the grips pretty cheaply- grips come in all sorts of fun colors...especially oury mountain bike grips...i have hot pink grips on my bike...but it's a mountain bike. although i'm sure they'd work fine for a commuter as well. waterbottles/waterbottle holders also often come in fun colors.

throw some stickers on it.

or you could go old skool and find some streamers and/or spoke jewelry. just kidding. sort of.