Silicon Photonics is experiencing a dramatic increase in interest due to emerging applications areas and several high profile successes in device and technology development. Despite early work dating back to the mid 1980s, dramatic progress has been made in recent years. Whilst many approaches to research have been developed, the striking difference between the work of the early to mid 1990s, and more recent work, is that the latter has been associated with a trend to reduce the cross sectional dimensions of the waveguides that form the devices. The question arises therefore as to whether one should move to very small strip waveguides (silicon wires) of the order of 250nm in height and a few hundred nanometres in width for improved device 2 performance but with little hope of polarisation independence, or to utilise slightly larger rib waveguides that offer more opportunity to control the polarisation dependence of the devices. In this paper we discuss devices suitable for one approach or the other and present designs associated both with strip and rib waveguides. In particular, we present designs of polarisation independent ring resonators with FSRs up to 12nm, we propose modulators for bandwidths in the 10s of GHz regime, and we present grating based couplers for rib and strip waveguides, and/or for wafer scale testing, as well as a novel means of developing Bragg gratings via ion implantation.