most common geckoes around at the moment are thicktails (Underwoodisaurus milii) these can be found tramping around anywhere on the ground at night, normally over dry leaf litter around rocky areas, Broad-tails (Phyllurus platurus) can be found around boulders, esp in colder damp areas, though these are really Sydney basin geckos and I'm not sure how plentiful they are around Newcastle, they can be found by there dozens in certain spots in Sydney though. Eastern stones (Diplodactylus vittatus) are found over a range of dry environments but never in numbers, I have only found a few in the Sydney area. Lesueur's velvets (Oedura lesueurii) are very common on dry sandstone area's, inc. ocean front cliff faces. In the newcastle area you can also get Robust velvets (Oedura robusta), these are found on verticle faces ie tree trunks and walls, though usually only one here and there.