SEO Lesson-Manage your dynamic page URL

What does people mean when refering to "dynamic web page"?? It is not about something "dynamic" as we might think, such as rotating image, some flash. Here, "dynamic" simply means the web page is connected with a database and some other language other than html is required, such as php and asp. Since we are talking about SEO, we will not get into detail thses server-side language.
Now, suppose my url looks like this:
http://www.bestpaltformbeds.com/platformbed/retrobed.php ---this is fine to any search engines

http://www.bestplatformbeds.com/platformbed/retrobed.php?png=2---This is still ok, at least with some of the search engines

http://www.bestplatformbeds.com/platformbed/retrobed?&ID=2234=CAD&=ID_97
Now, this kind of URL will cause me some trouble. A lot of parameters are contained in this URL. Thus, this page may not get indexed by Google or even if it get indexed, it would not get ranked in the top 30. So how can we get it fixed?
1. Modify URL so they does not look like they are pointing to dynamic pages. You can achieve that by removing some special characters such as #, !, ?, * and reducing the number of parameters.

2.Use URL rewrite trick---- you can look more in detail here httpd.apache.org/docs/mod/mod_rewrite.html