Salesforce Apex: Check if the current ORG is a Sandbox. / Required: Summer '14 (version 31.0)

OrgUtilities.cls

// To be used like:
// if (OrgUtilities.runningInASandbox()) { etc.. }
public class OrgUtilities {
        
    public static Boolean runningInASandbox {
        get {
            if (runningInASandbox == null) {
                runningInASandbox = [SELECT IsSandbox FROM Organization LIMIT 1].IsSandbox;
            }
            return runningInASandbox;
        }
        set;
    }
                        
}