Definition: So what are riblets and rib tips? These names have become interchangeable, but they are different cuts of meat. Rib tips are actually the very end (underside) of a rack of ribs. When a rack is trimmed to make St. Louis style ribs there is a thin strip of rib ends (or tips) left behind. Riblets are cut from back or spare ribs to straighten them out. Even notice how back ribs are rectangularly shaped? This is done by trimming the bones to make them straight. Largely this is done for presentation. There is something called rib buttons. These are not ribs, but back bone cuts.
In the past these small pieces often got thrown out. Now you can buy them in many stores and they are becoming much more popular. They are typically meaty and flavorful so they make a great dish, no matter the occasion. If you have trouble finding them, ask you butcher. They are now being packaged and shipped all over, but your local stores might not stock them so remember to ask. It is also likely that your local store may miss label these cuts because there isn't a great deal of standardization in meat cut names. The thing to remember is that whether you have riblets or rib tips they are going to cook very similarly so don't worry too much about what you are getting. From this point forward I'm just going to refer to rib tips to same time.
Cooking: There are several methods for preparing rib tips. They were popularized by the Applebee's Restaurant chain many years ago and they sell literally millions of pounds a year now. Applebee's grills and then steams their riblets to give them a charbroiled flavor while also making them tender. This is great if you are a busy restaurant that has to turn out hundreds of pieces a day. While you can go this way rib tips are great just grilled.
First of all remember that rib tips are still ribs. Low and slow is still the best way to make them. However, because of their size they cook quicker. A low, indirect gas grill fire for an hour or two, or a low charcoal fire is great for these little treats. Apply a good rub or just sprinkle with some seasoning and they'll turn out great. If you want barbecue sauce, brush it on at the end of the cooking time to prevent burning.
Smoking Of course you can smoke rib tips. They make a great appetizer while other things continue to smoke. Throw rib tips on the smoker about 3 hours before he guests arrive. Treat them as you would a rack of ribs and you can pull them off the smoker and serve them up while your guests settle in and get their drinks. This keeps them busy and happy while you finish with the main course.