Traditionally limited to large institutions like gyms, walk in showers have recently made the transition to domestic use, and are increasingly being installed in home bathrooms.

Walk-in showers (showers whose base is either level with the floor of the bathroom or very slightly raised) are an excellent choice for many reasons. Many people will pick them for their looks, which are substantially different to a regular shower/bath combination, but others will choose them for more practical reasons. They can be sited anywhere in a bathroom, and can be built to non-standard sizes, which makes them ideal for people with small, or unusually shaped bathrooms.

They are also much safer for day to day use, because the risk of tripping over a raised shower entrance is reduced to either zero (for a shower that's base is flush to the floor) or almost zero (for a shower with a slightly raised shower tray. This makes them an ideal choice for people who have difficulty walking or standing, or people with disabilities.

When you buy walk in showers, there are many factors to consider. 

Size and placement - Walkin showers can be bought in a number of standard sizes, and bespoke showers can be made to your specifications.  Really, the only limit is your needs.  If space permits, I would suggest picking a shower that is big enough to provide a feeling of luxury while showering (and which definitely has enough space for you to move around without bashing your elbows on the shower door), but one which is not too big to comfortably clean regularly. 

Shower doors - there are many different types of shower screen and door available - single doors, or double, sliding shower doors or doors that open outwards.  Frameless shower doors and shower enclosures are becoming increasingly popular, and look sleeker than their framed alternatives.  Also increasing in popularity are clear glass shower enclosures, which make a room seem more airy than frosted glass shower screens.

Shower heads - the whole reason for having a shower is to get wet and clean, but the shower heads are an often overlooked part of buying a shower.  There are many types of shower head available, from overhead heads that produce a rain-like effect, to side and floor jets that can provide pulasating and massaging bursts of water.  One of the biggest benefits of having an enclosed shower like this is that you are not restricted to just one shower head - for the ultimate in luxurious showering, why not have several, to drench you from all angles?

Walk in showers are an ideal choice for those with mobility issues, or disabilities.  Not having to clamber over the lip of a bath makes the process of entering the shower easier, and there is a much lower risk of slipping or tripping as you balance on one foot while you step into your shower.  Additionally, showers with wider than normal entrances can be installed to accomodate wheelchair users. 

Many walk in showers these days can also be provided with a shower seat, to make showering easier for those who have difficulty standing for long periods.  Some of the newer models even have padded shower seats for added comfort! 

Walk in showers are very similar in many ways to wet rooms, and the line between the two can be blurred.  If you have the space, and finances permit, I would suggest seriously considering a wet room as an alternative option, particularly if mobility is an issue.