I'm not exactly sure which forum is best for this question, so I'm just going broad in the Miscellaneous Theological section.
The question I'm asking about is an area where I admittedly don't seem to have a good grasp on things. However, a friend recently brought it up as wanting to discuss it at some point, so I wanted to get some direction and input from everyone. So, here goes... hope my rambling makes sense...

I recognize that Christians have no obligation to keep the Sabbath, as given in the Old Testament. I also recognize that that commandment was the only one that Jesus didn't mention directly in the New Testament. However, in terms of Sunday (The Lord's Day), does the Christian have practical obligations for what to do, or avoid? I know that in regards to creation, in Genesis 2:1-3, God rested on the seventh day... so, does the general concept of a "physical" rest still apply for us in any way, or should that be understood as spiritual? If there is still a place for the physical rest, does it make sense to attach it to what we now consider the Lord's Day?
Among Christian friends and acquaintances, so many view Sunday differently... some are very strict on what they'll allow themselves to do or not do, while others are much more free about what they allow. Some wouldn't think of going to a store or a restaurant, while others don't seem to have a problem with it. I hate to boil it down to such legalistic sounding questions, but, for example, should a Christian eat at a restaurant on the Lord's Day? Should they mow their lawn? The questions could go on and on, along those lines.
Can anyone offer some insight, or, correct me where I may have a poor understanding of things in this matter? I feel like I'm maybe missing something.
Hope my post made enough sense... thanks for any input!
-Ryan