The biggest inspiration was the link to an extremely cheap site for the production of PCBs, in fact 10 off 5cm x 5cm only cost $13 inc. postage. Ten PCBs for a tenner, Fantastic. Link
I used the Eagle files from Nathans site and modified them to suit my requirements by adding the connections for an SD card, a CR2032 battery holder, 2 extra DS18B20 probes and an LDR, both the DS1820s and LDR have switched power supply using an output pin. (idea from Martin's corner of the web)
The finished PCBs arrived today and they look pretty good.
I'll build one up later next week and get programming.
My next PCB is an add on board for my USBtiny ISP programmer so I can program a 328P, ATtiny84 or ATtiny85.
If anyone wants the eagle files for the PCB below then just let me know in the comments.
OOPS! noticed that the labels for the VCC, VCC1 and GND, GND1 are swapped over, the top pair are actually VCC and the lower pair are actually Grounds
3D rendering in Google Sketch up
Actual finished PCBs