The only person who probably wouldn't really benefit from walking would be someone who was already very fit. Thirty minutes walking a day, every weekday is considerate moderate exercise and will help to increase overall fitness plus being excellent for the health of the heart. Walking fast can be quite tiring though so it is a good idea to take a break or slow down every so often to relax the muscles and joints.
If you plan to do this then you will need a regular change of view to make it more interesting. There are a number of exercises which can be performed using a static machine including rowing, walking, running, stepping, cycling, skiing and even cross training.
If you are someone looking to shed a few pounds then there really isn't a better alternative than walking as it can be done at almost anytime and anywhere. Some other sports where walking is involved also have the added advantage of having a second exercise function like carrying a weight as in hiking where the rucksack performs the weight action.
Two other benefits of walking are the cost, if you don't have a great budget (but do get a good set of walking boots or similar,) and the fact that it is considered a low impact activity do should not damage the joints. You don't even have to start with the thirty minutes straight away but build up to it gradually so that within a few weeks you will be up to the 30 minutes a day.
The number of health benefits related to the simple act of walking are enormous and it is easy for anyone to do and if you have time why not join a club which should make it more interesting. If you have a budget to work with though, you may want to consider a home treadmill which can really speed up your fitness regime.
Treadmills are still the most popular exercise machine out there, but not everyone can use a treadmill safely, especially when it is to be used for running because of the often high impact exercise that is required. A treadmill consists of an endless belt on which a person can walk or jog with or without changing pace and using a treadmill will speed up your metabolic rate and allow your body to absorb and utilize greater quantities of the nutrients that you consume.
If you are buying a treadmill, don't skimp if it is something that is going to be used regularly and make sure it has a good range of functions, especially an adjustable ramp. The treadmill works for a lot of people who like to work out in the privacy of their own home.
You can snatch a few minutes here and there on the treadmill while dinner's cooking.