There's loads that can be done, literally hundreds, if not thousands of bandagings possible on the 3x3x3. As for the 4x4x4, there's only 10 bandagings if you restrict yourself to AxBxC variations or insist on some strict symmetries. Otherwise there's probably over 10,000 possible bandagings, which would probably require a lifetime for a human to explore them all (if it's even possible). For example, bandage a corner with an edge, and leave everything else the same. There's a new bandaging. Bandage a centre with an edge. There's a new bandaging. On the Revenge, bandage 2 centre pieces together. Once again, there's a new bandaging. A lot of these will create minimal difficulty increases over the original puzzle, others will vastly simplify it, and others still will turn the puzzles into your worst nightmare (eg. The Wall/Interleaved Cube). There's no law out there that says that bandagings HAVE to be symmetrical. Just look at the one that Meffert's selling for a case in point. Another "worst nightmare" one is the "Fisher 2" cube, a bandaging which, as far as I know, was developed by Greg Stevens, not Fisher. If you'd like to try one for yourself (sort of), bandage a 2x2 block on opposing sides of the cube, one directly above the other. Then bandage the 4 2x1 blocks adjacent to them on the top and bottom faces. Then let the fun (or torture, if you prefer) begin!