As discussed elsewhere in these pages, it is very hard if you're just starting out in radio to make potential employers aware of your talents.
Demo tapes work to an extent, but only if they manage to reach the right ears.
I'm setting up an on-line showcase which is open to anyone looking for work as a radio journalist. You send me a demo tape of no more than five minutes, plus you send me a potted CV of no more than one side of A4. I will provide an index page so that people can find you. I run an e-mail list which includes a vast number of radio stations and other media employers and I will notify them every time I update the showcase pages. Then it's up to you.