Psy don't potty mouth London too much.

Craig, I've lived in London all my life, I've never been successfully mugged that isn't to say that it's never been tried I've had 4 attempted muggings now, 1 I was in school still the other 3 were post 16. My advice should you carry your I-pod keep it hidden also sometimes buying cheapo black headphones works wonders since I-pod headphones are white and pretty distinct. Also be careful at ATMs watch your pin and try to use Barclays/HSBC/Nationwide Link ones if possible they're the hardest to install forgery devices on. Most ATMs in Central London will dispense 10s and 20s like normal however on a weekend expect 20s only to be available it's better to withdraw less and go more than once if needs be. Put the money straight in a pocket/wallet whist folding it to keep the number of notes disguised and be wary of anyone behind you male or female. Far more likely to get mugged after using a cash point than anywhere else. Use common sense you'll be fine, also try not to look afraid of gangs of youths because most muggers in London are opportunists if you look easy they'll go for it. Just if someone pulls a weapon don't be a hero just give them the stuff nothing you own is worth dying for and since you hear of crap like people being killed for £5.50 or so don't risk it. I'd still advise against going down dark alleys/side-streets in central London late at night however.

As for the Train if it's a return journey I suggest asking for a "Saver Return" ticket at the station far cheaper than any other type of return it can be brought at the ticket office and I'm pretty certain student cards are accepted too a child/student rate one could cost as little as £20 for Bristol to London. www.Thetrainline.com can be of more help there. Plan the journey also look at the tube map to see what connections you need to make because the underground is pretty confusing even to seasoned travelers, though nice people like myself or London underground staff will help you if you ask, though since most Londoners by nature are not nice people ask tube staff it's their job to help you.

As a side note London is increasingly better policed if you wish to make your parents more at rest tell them this. We've got large numbers of PCSOs and Police officers in all major areas/problem areas they've even started riding/patrolling the tubes and buses and parks too late at night to prevent muggings there. You can always ask a police officer for directions and also if you're lost and see a mini-cab office you can always ask them for directions they won't mind if they offer a cab it's up to you.

All in all, London is great multicultural society and the nice parts I wouldn't change for the world but the crap parts will forever be what makes London a crock of crap and since it's so old the good and the bad areas are often on top of each other.

This was written just after psy's post in this thread but yeah agreed with CZ and Dreddz. Also like I say, 90% or more of the time you can just put up a little front, make yourself look confident and self assured and people leave you alone it's when you look nervous/scared they go for you.