1. "It must be nice to have so much time off work." It might look to you like it's nice to have plenty of time to run errands and watch Netflix, but this will make you sound insensitive to the stress and anxiety of unemployment, which your friend is almost certainly dealing with. Being unemployed isn't a vacation. For many people, it's more stressful than going to an office every day.
2. "How many interviews have you had?" There's no way for this question to make your friend feel good. If she hasn't had many, she'll feel awkward explaining that. And if she's had a lot, she'll worry that you'll wonder why none of them have led to an offer. Don't put your friend in the position of explaining how successfully or unsuccessfully her search is going - after all, the only success that really matters is when she gets a job.
3. "Have you tried looking for jobs online?" Unless your friend is unusually inept with technology, she's looking for jobs online. Possibly daily. Suggestions of tried-and-true methods like this one can be aggravating for job-seekers, and can come across as if you don't have faith in her ability to manage her own search.
4. "Why don't you try temping?" While this can be a good suggestion for some people, temping isn't as reliable of an income source as it used to be. With so many people out of work and competing for the same jobs, even temporary ones, many qualified job seekers report that they've registered at multiple temp agencies and never been called.
5. "Did you apply for that job I sent you?" You're probably just asking out of curiosity or to be supportive, but it can put your friend in an awkward spot. She might have determined that job you sent wasn't right for her, or she might have applied and not appreciate your stirring up anxiety about why she hasn't heard back. It's great to pass along job opportunities that you see, but make sure you don't sound like you're nagging about them afterward.
6. "But you're so smart (or accomplished or well educated). You shouldn't have trouble finding a job." You might think you're being supportive, but since your friend apparently has had trouble finding a job, you'll either make her feel bad about herself (why hasn't anyone wanted to hire her if she's so smart?) or make her think that you're naïve about the very tough realities of today's job market.
7. "You hated your old job anyway." Sure, your friend might have hated her boss or not gotten along with her co-worker, but she would probably rather have the income from that job than not have any work at all.
8. "Have you heard back from that interview you had last week?" This is a good way to remind your friend of something she might be trying not to agonize over. When a job-searcher has good news that she wants to share, you'll hear it.
9. "Let's go out to (expensive dinner / concert / trip)." Without any income coming in, your friend is probably watching her budget, so be careful about the cost of any activities you suggest. The exception to this, of course, is if you're treating.
10. "It's taking you so long to find a job!" Don't expect your friend to find a job immediately or express surprise that she's been searching for so long. In this market, job searches take months, and in some cases a year or more. Comments like this can be excruciating for the job searcher, who might be working far harder than you know.