It is becoming more common for people to be asked what their favourite hobby or pastime is on a job application form. It is therefore advisable to include a section on your interests and any hobby that you are actively engaged in on your CV or Resume too. This helps to differentiate your application from all others that have similar experience and qualifications as you do. A hobby can be used as a great ice-breaker at interviews too and you may find yourself discussing your skydiving exploits more than your previous job. Obviously the more unusual the hobby the better as it is likely to make an impact on anyone reading your CV and be a point of interest that helps the reader remember your application over another.
It is important, wherever possible, to list hobbies or interests that clearly demonstrate relevant skills and accomplishments that are appropriate for the job your resume is being considered for. Obviously, if you are applying to be a cook for a company you would want to list cooking as one of your hobbies. This may seem an obvious point but you could also highlight other areas of the same hobby such as researching recipes or jam making for example.
It is advisable to be selective about the number of hobbies you list. If it seems that your time is taken up with a myriad of different activities a potential employer may reject your application for fear that you may never be available for overtime work if necessary.
Another possible impact of your choice of hobby may be if it involves a lot of travel or long hours. The potential employer may feel that your hobby would have an adverse effect on your ability to hold down a long term position and may think you are just trying to fit in work around your hobby and not the other way round.
Whatever you do, don't make up a hobby purely to get a job. If you say you are a chess player, to indicate that you are a logical thinker and forward planner that is great if it's true but beware, you may find that you are challenged to a game by your boss and be rumbled on the first day!