GPS and mobile phone navigation have come on in leaps and bounds in recent years, BUT BE WARNED. In the Highlands there is often no signal and journeys in rough country often take longer than planned and battery power is all important. ALWAYS take a good map AND a compass and know how to use them. I cannot tell you how many times that I have come accross people totally lost and all they are navigating by is some form of electronic navigation. Towns are fine, at least, you can ask someone, out on the hill is another matter entirely! Sorry to be boring about this, but............
Very sensible advice the police are always harping on about this on the radio.

In general I think we are a safe country. I'm sure my wife wouldn't think twice about heading off on her own or with a couple of girl friends (if she could get the green light!). It is just a matter of being sensible and not wandering around certain areas (which are easy to spot!) late at night with a big camera/expensive designer bag/ayephone on show - sensible precautions the world over.

I've never felt the least threatened (and I am eminently "beatupable") any "unpleasantness" I've encountered have simply been idiot comments which are easy to ignore.

Hotels, B&Bs, youth hostels etc are generally good and friendly. My wife and I generally choose a decent B&B as they are more personal and friendly but with a healthy dose of comfort; but I recognise they tend to cater for couples (a single traveler will usually pay a premium). Youth hostels are are a good option if you don't mind "roughing it": they are cheap and very wide ranging (some are ancient mansions or castles, old railway carriages and can be very well placed... some have the best views in the UK). A mix of people use them (i.e. not only those visiting from abroad) so it is a good place to meet a variety of people including those local to the UK, drink some wine from a tea cup, whisky from a bottle and chat late into the night if that is what you want to do... if not bring some ear plugs!