The above code:
activity.startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(url)));
Is correct and functional, I just thought I'd mention that you can also embed a browser in your view pretty easily with a WebView, like so:
<WebView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/webview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
WebView apparently is not an available view from the list in eclipse so you have to add the XML manually, but it's neither difficult nor time consuming. Once you've got your web view you set its url (and other important properties) thusly:
WebView mWebView;
mWebView = (WebView) findViewById(R.id.webview);
mWebView.getSettings().setJavaScriptEnabled(true);
mWebView.getSettings().setBuiltInZoomControls(true);
mWebView.loadUrl("http://www.google.com");
Hope that was helpful :)