CafePress via Groupon offers a Customized Case for iPhone 3G, 3GS, or 4 in White, Pink, or Silver for $15. That's $15 off, tied with our mention from last week, and among the best deals we've seen for a custom iPhone case. Limit four per person. Customize the case with uploaded images or personalized text. Shipping is not included in the deal; it starts at $5.25. The credit is valid from January 16 through May 16. Deal ends January 13.