We review our recent experimental progress regarding optical metamaterials and transformation optics. Herein, we emphasize

(i) reconstruction of the phase images in three-dimensional, visible-frequency, broadband, polarization-independent carpet cloaks;

(ii) tapered gold-helix metamaterials as circular polarizers with 1.5 octaves bandwidth;

(iii) collective effects in second-harmonic generation from split-ring-resonator arrays at telecom frequencies;

(iv) metamaterial bolometers.