What is beyond gamma rays and radio waves in the electromagnetic spectrum? The electromagnetic spectrum is commonly referred to as consisting of;
radio-waves, microwaves, infrared, visible light, ultraviolet, X-rays, gamma rays - of increasing frequency from left to right.
But is it possible to get radiation of higher wavelength than radio waves, or lower wavelength than gamma rays - does it even exist? Or could they be produced?
Most interestingly, from the Planck–Einstein relation, $E = hf$, how high of an energy could you get for a very very high frequency radiation?
 A: In addition to the answer by dmckee and to answer the question how high in energy you could get a photon it might be worth thinking about 'Gamma Ray Astronomy' where the highest energy photons are detected. The record highest photon energy observed is apparently currently 80 TeV, which corresponsds to a wavelength of $1.5 \times10^{-20}m$ wavelength (if I calculated it correctly). This is very short considering the 'size' of the hydrogen nucleus is ~$1.8\times10^{-15}$.....
...but, of course, as dmckee points out there is a continuous spectrum and no high or low energy limit to the energy of a photon.
A: Higher energy gamma and longer wavelength radio? 
Keep in mind that the different 'kinds' are merely human labeling conventions for a spectrum that is continuous in the mathematical sense. There is no feature of "radio" that distinguishes it objectively from microwaves. We just pick a boundary on the basis of some technological limitations that apply when we decide the difference and stick labels on.
The reason there aren't labels beyond radio and gamma is that there is no real need to label those bands.
A: There is a theoretical limit for how small the waves can be. it is when the waves are as long as the Planck length. But as far as I know there isn't a limit of how long the waves can be.
A: After 6 years you can pretty much answer your question on Wikipedia: Ultra-high-energy gamma rays are relevant in astrophysics and very large radio waves can be used to communicate with submarines.
Ultra-high-energy gamma ray
Extremely low frequency
A: Wouldn't a wave smaller then the smallest be "in the same theoretical universe of discourse" mathematically negative? Looks like a good explanation for a time traveling Sci-Fi xD
Also, wave may be able to reach a higher speed then it's correlation to length. For example if traveling on a referent that is also traveling. A wave inside another one would be 2 time faster if we can alter it's spatial referent, for which quantum intrication could be the key.
Don't forget that all those equations have or are directly correlated to a constant. Those are human made, at least human labelled.
Thinking about it in separate questions was a good lead, what would happen over gamma ray speed/frequency, to an electromagnetic signal, imagining we have a transmitter that can achieve that?
A: Beyond radio waves are mega-giga-super-long waves as the wavelength approaches infinity; the longer they are, the more they dissolve into nothingness because once half the wavelength $\frac{λ}{2}$ gets more or less bigger than the radius of the entire universe, they cannot really interact with anything. In other words, they practically cease to exist and their energy approaches 0.
Beyond gamma rays are mega-giga-ultra-death rays that are more and more ionizing. Wavelength could be made arbitrarily short as long as it is larger than 0, but good luck gathering amounts of energy to generate such rays. Main difference is that "usual" gamma rays just knock off electron clouds from atoms, break bonds and cause radiolysis of matter, while mega-giga-ultra-death rays instantly turn any state of matter into hot plasma.
