Can you ever register with too many recruitment agencies when looking for a job? Really the more you register with the higher your chance of finding a job but be aware that most are highly proactive and you may find that you are bombarded with calls and emails regarding posts that they believe you may be interested in.
Be aware that some agencies also contact you regarding a position that is not actually being advertised through them and many employers will only advertise their jobs direct as to avoid big recruitment fees that some agencies charge. Register with a few to start with and see how it goes, if you are not happy with the results you are getting register with a few more at a time. Do not just sit back though and expect a job to land in your lap, you should also be looking on local jobs boards and newspapers for the job you wish to apply for.