Hi guys,
i want to share with you a solution I come up with, to wrap long url when rendering a VF page.
Basically the problem was this:
A customer pasted a very long URL (more than 400 chars) in a Rich Text Area. When rendering the page as PDF, to print it, the URL overflow the page margin, so it wasn't visible at all.

This is the code i come up with

private String addWhiteSpaceInUrlTooLong(String text) {
        // Step 1 - Search anchor links
        Pattern ptn = Pattern.compile('<a[^>]*(>.*?)</a>'); // WATCH OUT! This regex doesn't match nested anchor
        Matcher mch = ptn.matcher(text);
        Integer charPerLine = 50; // A whitespace is inserted each charPerLine chars
        while (mch.find()) {
            String toReplace = mch.group(1);
            String substitute = '';
            Integer len = toReplace.length();

            if (len < charPerLine) //No need to replace
                continue;

            Integer elems; // White space to insert

            if (len / charPerLine == 0)
                elems = len / charPerLine;
            else
                elems = len / charPerLine + 1;

            // Insert white spaces
            for (Integer i = 1; i <= elems; i++) {
                if ((charPerLine * i) < len)
                    substitute += toReplace.substring(charPerLine * (i - 1), charPerLine * i) + ' ';
                else
                    substitute += toReplace.substring(charPerLine * (i - 1), len) + ' ';
            }

            text = text.replace(toReplace, substitute);            
        }

        // Step 2 - Search pasted links
        ptn = Pattern.compile('\\b\\s(https?://\\S.*?)(\\s|$)');
        mch = ptn.matcher(text);
        charPerLine = 60;

        while(mch.find()) {
            String toReplace = mch.group();
            String substitute = '';
            Integer len = toReplace.length();

            if (len < charPerLine)
                continue;

            Integer elems;

            if (len / charPerLine == 0)
                elems = len / charPerLine;
            else
                elems = len / charPerLine + 1;

            // Insert white spaces
            for (Integer i = 1; i <= elems; i++) {
                if ((charPerLine * i) < len)
                    substitute += toReplace.substring(charPerLine * (i - 1), charPerLine * i) + ' ';
                else
                    substitute += toReplace.substring(charPerLine * (i - 1), len) + ' ';
            }

            text = text.replace(toReplace, substitute);
        }

        return text;
    }

You could use like this:

MyCustomObject.richText = addWhiteSpaceInUrlTooLOng(MyCustomObject.richText);

Hope it will be useful ;)