There's not a centralized place on this forum that has a collection of images / swfs for use... at this time (not implying one is coming soon... but a resource area might be a good request in the future).

You can browse the various samples that people post a link to... and if you see something that you like, you could ask them for the source. But be prepared for some to say no... they've worked hard creating a custom visual interface and can't be expected to turn over the work.

Any jpg / png image can be used as a hotspot... so you can search the web for "icons" or something similar such as "arrow icon"... and just see what you find. Pay attention to any license information you find on the site. A lot of "free" stuff is listed as free for personal, but pay / attribution for commercial use.

two possible icon sources are...
http://www.iconspedia.com/
http://commons.wikimedia.org/wiki/Crystal_Clear

Once you find something that you like... and the license allows... you could always modify it in an editor of some sorts. GIMP and InkScape are free and capable.

If you want to use a flash based icon... then there are a lot of sources out there. I think a popular one is flashden.net and a search for "flash icons" might turn up some more. BUT... some flash.swf's don't play well with krpano... or require flash editing capabilities to get them how you want them.