The way I understand it, the LGPL, unlike the GPL, can be linked by software not licensed under the same license. So you can't just take a piece of the library and insert it into your program. What you can do, however, is ship a binary version of your program linked to a binary version of the library, but you will still need to offer your customers access to the library's code, not your program's code, if they request.
If you're not aware of this, both the GPL and LGPL explicitly allow you to charge for any changes you make to the code, as long as you offer the code for the price of distribution. Ubuntu, for example, does this. They ship their binary CD for free (even though they could charge for it) and charge $1.95 for the source CD.
Hope this helps! Don't forget to check those links.