PREVIOUS ADVICE 
I am in the process of applying for funding at the postdoctoral/young investigator level. I wondered if there were any successful grant applications available online that could act as a guide for format, scientific content, etc. It would be helpful to see what a successful grant application was like.--CL
You bring up a subject that almost every postdoc and young scientist I speak with wants: to read and see funded grant applications. You're in luck: As part of Next Wave's Career Development Center we will soon start a guide to grant writing. That guide will include online postings of funded applications from the National Institutes of Health (NIH), the National Science Foundation (NSF), and other funding agencies. Complete with each application will be a short description of its format and content and also the reviewer's comments.
Making entire applications available online requires authorization from the applicant, and I haven't come across any sites that provide such information. Applications are currently being solicited from the scientific community, which will be included in our database only with the applicant's consent. Officials at NIH and NSF do not see a problem with releasing such information if principle investigators and collaborators agree to participate.
If readers would like to contribute their applications--to give upcoming postdocs and young scientists an idea of what makes a winning grant application, please e-mail me the research plan and reviewer's comments (if you have them) or send them to:
Science's Next Wave
American Association for the Advancement of Science
1200 New York Avenue NW
Washington, DC 20005
In the meantime, you may want to check out NIH's CRISP  (Computer Retrieval of Information on Scientific Projects) database. You can search for current or "historical" federally funded biomedical research projects and get information on "scientific concepts, emerging trends, techniques, or identify specific projects and/or investigators." The return after a search gives you the abstract of the winning application and other details of the grant award such as length of duration and the review group that evaluated the original application.
The NSF provides a similar awards database  of abstracts from 1989 to recent awards, with information regarding duration of award, how much the investigator received, and the program manager at NSF who handled the proposal.
Comparing abstracts relevant to your own scientific discipline can provide insights into how you can tailor your own research abstract. It's not the same as seeing the entire application, but it's a start.
-- The GrantDoctor
When do I have to apply for funding if I want to start doing a Ph.D. next autumn? Can I start doing this after 3 years of study despite the fact that I am registered to do a 4-year MSc. course?
A Master's degree is not a prerequisite for entry into a British Ph.D. program--a Bachelor's degree or equivalent is often enough, so in theory you can apply for fellowships and funding at any time once you have this level of qualification.
Many students start scanning the horizon a year or so ahead of time while still finishing up a project or a course--just like you are considering to do now, and it can prove a worthwhile procedure. Unlike in the States where you can "rotate" through several labs before settling down in one that interests you, in the U.K. you get slotted into a specific project or lab right from the start--so making the right choice takes time and thoughtful consideration.
The keyword here is "Time." The earlier you start your search the better: Many funding agencies in the U.K. for example, do not accept applications directly from the prospective student but from the university in which they wish to study. The Medical Research Council  (MRC), for example, suggests that students seeking Research Studentships leading to the Ph.D. degree "approach the Head of the Academic Department or the Director of the MRC Establishment where they would like to train." Such granting organizations consider the sponsoring environment to ensure that the training, supervision, and assessment of students are well-suited to the proposed project and the candidate.
This will all take time to organize, so do your homework, call around, set up some appointments with the department head, and discuss your options.
The National Environment Research Council  (NERC) also has the same policy of awarding the grant to the university department nominating the student and so you should contact universities to see if they have an approved NERC award. This gives you the opportunity to find out what possibilities lie ahead the following year: Departments may expect to receive funding for Ph.D. projects the same time you finish your Master's degree for example.
By talking to institutional departments early on, you may be able to earmark which have interesting projects lined up or at least establish yourself as a good candidate when the department advertises the position.
The Engineering and Physical Sciences Research Council  follows the same pattern. Their nomination forms become available to universities and institutions around February or March and must be submitted by 31 July for awards starting the following academic session.
You may have to provide the universities you are interested in with a biographical sketch and perhaps an outline of why you want to pursue a Ph.D. and what you understand about the proposed research. For some awards, like those given by the Biotechnology and Biological Sciences Research Council , you write, complete, and submit the application to your desired department who then goes on to nominate you. Those studentships begin around October.
So there is a lot to do and a year isn't a long time. You can get things under way, seek out potential departments, and ensure them that you will complete your Master's next year and get your paperwork in order.
-- The GrantDoctor