As an engineer I make calculations everyday and I'll upload them to the ExcelCalcs site. Here are my reasons for doing so (and they are not all altruistic):
a) I'll be able to find it easily in the future using the site search engines. Why live with the frustration of not being able to find a calculation you vaguely remember putting on some long lost hard drive?
b) If there are any mistakes other users will spot them.
c) Spreading knowledge makes me feel good.
Don't be a plunderer, be a contributor - upload a calculation today?
Repository Update
1) Buckling stress of a curved flat plate with all edges simply supported.
2) Find the centre point of a circle drawn through three points
3) Alex Tomanovich updated a couple of his structural spreadsheets for seismic loading analysis (IBC2003E.xls and IBC2000.xls).Back from Holiday - Whilst I was away on holiday soaking up the Tuscan sun I was pleased to see that the ExcelCalcs site carried on working without any supervision signing up a further 411 users.
No Rights to install XLC? - Many people are not given software installation rights at work and this prevents installation of XLC using the setup program. You may be interested to know that there is a manual installation method available which may get around this problem.