Hi!
I've been reading you guys for a while now but never posted anything. I think this is my first post so, hi!
I just wanted to share with you a free tool I've made, called DSO Browser:
http://dso-browser.com
It allows you to answer questions like "Which DSOs can I see from my lat/long, 8th magnitude or less, between 8 pm and 4 am, reaching 45 degrees above the horizon for at least 2 hours?"
That's one of the key things: to be able to specify a minimum altitude and time above that altitude, very useful for astrophotography but observational as well.
It has several features, such as auto-location, find objects by type (Galaxy, Nebula, etc), apparent magnitude and size, minimum altitude, etc. Just bear in mind that any filters you set will restrict the search more and more, so leave some options empty if you're not sure what you're looking for.
Also, when you see any object's details you'll see a Google Sky Map embed showing the actual stuff plus nearby object for you to actually browse the sky jumping from object to object, getting details, the best time of the year to see each DSO from your location, etc.
At the bottom of the page there's a contact form you can use to let me know your suggestions. I'm planning to include more features, but I believe I managed to get a decent enough version to share with you so those who wanted to use it could benefit from it.
Please note: this is not an exact application, just approximate enough to help in your observation/astrophotography sessions, so don't expect 'surgical precision' in the calculations
Hope you like it, I look forward to your comments!
Clear skies,
Sebastian