The Pseudo-Cl technique has a long heritage for curved-sky analysis of the CMB. By computing the angular power spectrum across all pairs of spectral channels, Cl(z,z'), this technique can be easily adapted to 3-dimensional intensity mapping surveys. The Cl(z,z') quantity contains all the information in the power spectrum, and it has several advantages to a traditional power spectrum analysis. It deals better with large surverys since no flat-sky approximation is required, it does not assume any underlying cosmology, it deals naturally with inhomogeneous angular and line-of-sight weights, and it naturally allows for the inverse covariance to be used to deweight foreground variance. The Cl(z,z') technique is also simple to convert to fast Fourier analysis on small angular patches. I will explain the advantages of this analysis technique and highlight a recent example of the technique applied to a galaxy survey. I will also review my own work using this technique to cross-correlate FIRAS data with BOSS galaxies and to simulate the sensitivity of the EXCLAIM experiment, using a flat-sky version of Cl(z,z').