Recent BABAR and Belle results on rare B decays involving photons or lepton pairs are reviewed. New preliminary limits from both experiments for B[yields][rho][gamma] and B[sup 0][yields][Omega][gamma], and from BABAR for B[sup -][yields] K[sup -][nu][bar[nu]] and B[sup+][yields][tau][sup+][nu][sub[tau]] are presented. Also summarized from the past year are Belle measurements of B[yields] X[sub s][ell][sup+][ell][sup -] and B[sup 0][yields] K*[sub 2](1430)[sup 0][gamma], preliminary BABAR measurements of B[yields] X[sub s][gamma], and preliminary results from BABAR and Belle on B[yields] K[sup (*)][ell][sup+][ell][sup -]. No significant deviations from Standard Model predictions have yet been found.

The authors present recent results on rare B meson decays based on data taken by the BABAR detector at the PEP-II asymmetric ee− collider. Included in this report are measurements of branching fractions and other quantities of interest for several hadronic, radiative, electroweak, and purely leptonic decays of B mesons.

Recent BABAR results on rare B decays involving flavour-changing neutral currents or purely leptonic final states are presented. New measurements of the CP asymmetries in B [yields] K*[gamma], B [yields] K*[sub 2](1430)[gamma], and b [yields] s[gamma] are reported, as well as a new measurement of the B [yields] K*[gamma] branching fraction. Also reported are updated limits on B [yields] [mu][nu] and recent measurements of B [yields] K(*)[ell][ell] and b [yields] s[ell][ell]. The data sample comprises 123 [center-dot] 10[sup 6] [Upsilon](4S) [yields] B[bar B] decays collected with the BABAR detector at the PEP-II e[sup +]e[sup -] storage ring.

New preliminary BaBar results for rare leptonic decays B[sup -][yields] K[sup -][nu][bar[nu]] and B[sup 0][yields][ell][sup+][ell][sup -] are reported. Using data collected at the[Upsilon](4S) with the BaBar detector, no evidence for a signal was found yielding the corresponding upper limits at the 90% confidence level:[Beta](B[sup -][yields] K[sup -][nu][bar[nu]])

We will present the most recent results on leptonic B decays B{sup {+-}(0)} 2!K*{sup {+-}(0)}[nu]{bar [nu]} and B{sup {+-}} 2![mu]{sup {+-}}{nu}, based on the data collected by the BaBar detector at PEP-II, an asymmetric ee− collider at the center of mass energy of the [Upsilon](4S) resonance. Rare B decays have always been a standard probe for New Physics (NP) searches. The very low Standard Model (SM) rate of these decays often make them unaccessible with the present experimental datasets, unless NP effects enhance the rate up to the current experimental sensitivity. Moreover, as NP effects can modify the decay kinematic, particular attention must be paid in order to perform a model independent analysis. A B-Factory provides an unique environment to investigate these processes. The high number of B{bar B} pairs produced by a B-Factory often allows to approach the needed experimental sensitivity. Moreover, the clean environment and the closed kinematic of the initial state enable to obtaining a very pure sample where to look for these decays.

The PEP-II and KEK asymmetric B factories are providing the BaBar and BELLE collaborations large samples of B mesons, enabling high-statistics searches for rare B decays. The rates for some of these decays can be enhanced by contributions from new physics, while others can provide constraints on the Unitarity Triangle. The author reviews a variety of recent results on rare B decays from these two experiments.

Recent results from Belle and BaBar on rare B decays involving flavor-changing neutral currents or purely leptonic final states are presented. Measurements of the CP asymmetries in B {yields} K*{gamma} and b {yields} s{gamma} are reported. Also reported are updated limits on B{sup +} {yields} K{sup +}{nu}{bar {nu}}, B{sup +} {yields} {tau}{sup +}{nu}, B{sup +} {yields} {mu}{sup +}{nu} and the recent measurement of B {yields} X{sub s}{ell}{sup +}{ell}{sup -}.