I still love my Thinkoutside keyboard https://www.cnet.com/reviews/think-outside-stowaway-universa... had it since my Nokia E61 and use it weekly. Only issue I've had so far has been that the photo support finally broke, other than that it works like new. Really great size to type on, decent travel and folds down to a great size.
I still have my Thinkoutside keyboard from the Dell Axim days as well. I’ve tried a few more recent folding keyboards, but nothing has met the rigidity, compactness, and key feel of that old thing. It was truly a magical product for its time.
Real shame they stopped making them ages ago.