Consider keeping the kit lens for general purpose photos. And take a look at the Canon 28-135mm IS. Optically it should be much better, it's a little longer, and the image stabilization will help you with long shots. I can personally vouch for the 28-135 IS, too. I have used it for years and sold quite a few photos taken with it.

Read and write reviews for the Canon 28-135mm IS lens >>

Please post a review for your XTi, too! We need more reviews for that camera. Don't worry about whether you've had it long enough or are qualified to post. Everyone is qualified and everyone's experience is valuable. Plus, if you want to update your review later, just let me know.