As a wedding planner, my clients frequently ask me if they should assign seating at their receptions. My reflex answer is "Yes!" but it really depends on the circumstances of your celebration - every wedding is different.

Terminology:
Escort card: A card with a guest's name that notifies them of their assigned table. Escort cards tend to be easier for the guests to navigate than seating charts, as escort cards are displayed in alphabetical order, making it easy and quick for guests to find their name. And, because each guest has their own individual card, you have to remake/add only those cards affected by a last minute RSVP change, instead of having to recreate an entire chart. An escort card directs guests to their assigned tables, but allows them the freedom of choosing their seat at those tables.
Place card: Communicates the exact seat where a guest is to sit, usually placed as part of the place setting. It is recommended that escort cards be used with place cards so that guests are not left to walk around every table, searching for their place card.

Here are some examples from two different Something To Celebrate weddings with flower themed table assignments (click for larger view):

Escort card

Place cards

The Cons:

• Assigning each guest to a table and/or specific seat is a lot of work, taking relationships and anticipated preferences into consideration.
• Pressure - what if you make a mistake in assuming who a guest would like to sit with? Oh, the pressure!
• Changes - Unfortunately, it is not uncommon to receive RSVP changes up to the day before the wedding. That means redoing your seating chart, escort cards, place cards....

The Pros:

• Your guests will appreciate being seated with their friends and families, without feeling the need to "save" seats.
• Money saving - by assigning tables, you ensure that every chair is used. By avoiding empty chairs, you avoid the need for extra chairs and even extra tables, which will also eliminate the need for extra linens, centerpieces, place settings, etc.
• Space - by avoiding the need for extra tables and chairs, you free up more space for your dance floor. Par-tay!
• Place/Escort cards are a wonderful way to communicate meal choices to the catering staff. If your guests RSVP choosing one of several entree options, the design of your place card can be a secret code that reveals those pre-made choices to the wait staff. For example, "beef" entrees could be indicated by the monogram/logo/design on the left side of the card, "fish" on the right.
• The escort cards afford you another decor opportunity! Some may see this as a "Con," I suppose... but not those of us who I love stationery. :)

Other points to consider:

• You'll want to reserve tables for your friends and families who will be involved in the post-ceremony pictures, since they'll most likely be the last (other than you, of course) to arrive at the reception. Often times my clients realize while assigning those seats that they're working on assigning seats for so many guests that they may as well assign everyone else while they're at it.
• Most of our clients assign tables, but not seats. This is a little easier for you, and also allows your guests to figure out exactly who they sit next to - so you're really assigning groups to tables rather than individuals to seats.
• Assigned seating will enhance the elegance of your atmosphere. If you want a very casual feel, do not assign seats to those other than those who are involved in post-ceremony pictures.

Whatever your choice, don't let the little details overwhelm you. Remember that the point of all of this hard work is a fabulous celebration with the people who love you most, on an amazing day.

Happy planning! :)
jessica