These guys sell Titanium and Aluminium fasteners in many sizes and special sizes for motorcycles and MTB and road cycling. I've bought from them before and they are great. They are US based, but they have some damn cheap shipping options to AU, and you can pay by paypal now too which is good.
Since a bit of variety seems to be welcome here recently, I thought I'd share this coupon I just got emailed to me. Fine print is…
Orders over Thirty Five Dollars receive a 10% discount. Orders over $100 receive free shipping on top of your discount. This coupon can be used twice per customer.
Ti bolts are relatively expensive, but they are strong and light and are perfect for certain applications where low weight is beneficial without compromising strength.
Aluminium bolts are cheaper but only useful for low weight applications where strength is NOT required.
Sure, you can get certain bolts slightly cheaper on eBay, but at least with these guys you know you are dealing with an actual company. ie. There are certain parts you wouldn't want to fall off/jam due to a failed fastener, such as a brake calliper.