You already know about in-house seminars–are you using them to full advantage? In-house seminars are an effective way to meet prospects in person, and many of your clients would be willing to help you meet their peers in an educational format. Often, where they might be unwilling to introduce you one-on-one, they'll work hard to create an event at their office.
Unlike "lunch and learns," whose educational component is brief, these in-house seminars can last up to an hour. Make sure you have a sign-up sheet for attendees' contact information.