It's a bit weird, to put it mildly, that Apple's iPhone Web apps site doesn't have an iPhone friendly version.
Makes you wonder how seriously they really ever were about the once celebrated Web apps.
The list is actually pretty interesting. For example: Apple - Web apps - Productivity, including 43 Actions,
I think the best way to install these is to browse the list from Safari/Desktop (on your iPhone sync machine), bookmark those you want to try, then sync to iPhone Safari.
From iPhone Safari you can turn these into standalone icons as desired.