Welcome from an expatriate Aussie.
Originally posted by Suzie Any advice on good everyday, walk around lenses that would suit my camera would be appreciated thanks.
Your 18-135 is a good start. Any further recommendation I would give is based heavily on where you are and what you are doing on your walkarounds. For example, last time I was in Sydney with my family, my K-5 and 18-135 were the go-to for almost everything with one exception: I took the 15mm f/4 Limited for the ships at the maritime museum. Gotta have wide angle when you go inside those. On my last visit to Melbourne, I'd just completed my collection of the Limited-series DA primes, so I brought them with me to try out and the 21 and 40 got most of the on-camera time in the CBD. Out in the country (e.g. some of the large towns in Gippsland), I'd take the 18-135 for a one-lens solution any day. Down at the beach? Queensland or NT? Snow? Gotta be WR; 18-135 is the go-to.
Shoot with your 18-135 for a while, and you'll gradually get a feel for the focal lengths at which most of your shots are clustering. Then you can think about spending money on specific lenses of a particular focal length. The two lenses you have right now will probably cover 99% of your needs for some time to come, and it's the shots you have trouble getting that will clue you in to where your money needs to go.
First, though, I'd buy a good tripod and a decent swivel-head flash.