I know that there are some caching classes introduced in the iphone sdk recently, and there is also a TTURLRequest from three20\'s library that allows you to cache a request
You can save an HTML in the documents directory and load the page directly from the documents directory on launch.
To save the webview content: Reading HTML content from a UIWebView
To load:
NSString* path = [[NSBundle mainBundle] pathForResource:@"about" ofType:@"html"];
NSURL* url = [NSURL fileURLWithPath:path];
NSURLRequest* request = [NSURLRequest requestWithURL:url];
[webView loadRequest:request];