Hama have updated their Lens Pen with a triangular head making it even better than before. I gave the previous version 5 stars, so Amazon are going to need to change to a 6 star rating system!
The pen looks and feels quite tacky but it is a great piece of kit with a compact size overall. At one end you have a retractable brush which is great for flicking dust and dirt off lenses and cleaning out the threads, where mischievous particles can lurk. I found it most effective to use the brush in combination with a blower. The other end of the pen is a soft velvety pad dabbed in some sort of cleaning agent held in the cap. This can be used to wipe clean smears, grease, and stubborn dirt from the glass by making small circular motions, like a spirograph. The new triangular shape makes it easy to get into edges and corners, which is particularly useful since this pen is also great at cleaning screens on a number of electronic devices - it's not just for lenses!
One note of caution... the brush is some kind of nylon or other artificial fibre. I would suggest that you never attempt to brush your DSLR's sensor with it since there is some potential for static discharge.
All in all, this is a great product. No worrying about cleaning solutions, and at least as effective as a lens cloth. Highly recommended!